
Class _Z7M 



/# 



; 



Boiler Safety Orders 



25018 
»' 



Issued by the 

Industrial Accident Commission 

of the 

State of California ) [fi 



-2 



Effective January 1, 1917 



California 

State Printing Office 

1916 









x r V .A 



INDUSTRIAL ACCIDENT COMMISSION 
OF THE STATE OF CALIFORNIA 



525 Market Street, San Francisco 

423 Union League Building, Los Angeles 



A. J. PILLSBURY. 
WILL J. FRENCH, 
MEYER LISSNER, 

Commissioners. 



JOHN R. BROWNELL. 

Superintendent of Safety. 



D. of B. 
OCT' It 1918 



m 



SUMMARY OF THE SAFETY PROVISIONS. 

of the 
Workmen's Compensation, Insurance and Safety Act, 

Chapter 176 of the Laws of 1913. 

[Sections 51 to 72, inclusive, of the Workmen's Compensation, Insurance 
and Safety Act give the Industrial Accident Commission power to make and 
enforce safety orders, rules and regulations, to prescribe safety devices, and to 
fix safety standards. It also empowers the Commission to appoint advisors 
who shall, without compensation, assist the Commission in establishing standards 
of safety. The Commission may adopt and incorporate in its general orders 
such safety recommendations as it may receive from such advisors.] 

The Commission, carrying out its plan of obtaining the best prac- 
tical ideas to incorporate in its Safety Orders, asked various 
interests to serve on committees to draft Boiler Safety Orders. 
These committees were named after consultation with the Gen- 
eral Safety Orders Committees, which were organized in San 
Francisco and Los Angeles, and which assisted the Commission in 
the preparation of General Safety Orders which went into effect 
January 1, 1916. 

As with the General Safety Orders Committees, one Committee 
on Boiler Orders met in San Francisco, the other in Los Angeles. 



San Francisco Committee on Boiler Safety Orders. 

George A. Armes (chairman), representing the Union Iron Works, as manu 
facturers of Boilers. 

(Frederick Birdsall, alternate to Mr. Amies.) 

J. B. Warner (vice-chairman), representing the Hartford Steam Boiler Inspec- 
tion and Insurance Company. ." ■ 

E. R. Killgore, representing the Standard Oil Company, as users of Boilers. 

D. P. Delury, representing the Board of Public Works of San Francisco. 

M. J. McGuire, representing the Boilermakers and Shipfitters Union. 

W. R. Towne, representing the International Union of Steam and Operating 
Engineers, Local No. 64. 

Chas. A. Smith, representing the California Metal Trades Association. 

John Mitchell, representing the International Union of Steam and Operating 
Engineers, Local No. 507. 

R. L. Hemingway, safety engineer, Industrial Accident Commission. 

John R. Brownell (secretary), superintendent of safety, Industrial Accident 
Commission. 



Los Angeles Committee on Boiler Safety Orders. 

Fred J. Fischer (chairman), representing the National Association of Steam 

Engineers No. 2. 
H. L. Doolittle (vice-chairman), representing the Southern California Edison 

Company. 
J. J. Malone, representing the Hartford Steam Boiler Inspection and Insurance 

Company. 
William H. Carter, chief city boiler and elevator inspector, representing the 

City of Los Angeles. 
S. M. Walker, representing the Pioneer Boiler and Machine Works. 
J. L. Glennon, representing the Fidelity and Casualty Company of New York. 
M. E. Carroll, representing the Steam and Operating Engineers No. 72. 
E. C. Jordan, representing the Firemen's Local No. 220. 
H. L. Boyd (secretary), safety engineer, Industrial Accident Commission. 



CONTENTS. 

Page 
BOILER SAFETY ORDERS _ — vii-xiii 

INDEX TO BOILER SAFETY ORDERS xiv-xv 

A. S. M. E. BOILER CODE, WITH APPENDIX 1-114 

INDEX TO A. S. M. E. CODE 117-147 



BOILER SAFETY ORDERS. 

Order 800. Inspection of steam boilers. 

(a) All steam boilers operated in the State of California, except 
those exempt by (b) of this Order, shall be subject to a regular 
internal and external inspection each year, if in service at any time 
during the current year, except that an interval of fourteen (14) 
months may be allowed when necessary. 

(o) Exemptions: The following boilers are exempt from inspec- 
tion by the Industrial Accident Commission : 

1. Boilers under the jurisdiction of the United States. 

2. Boilers of railroad locomotives used in interstate commerce 

and boilers under United States inspection. 

3. Boilers used exclusively for agricultural purposes. 

4. Boilers of twelve (12) horsepower or less, on which the 

pressure does not exceed fifteen (15) pounds per square 
inch. 

5. Automobile boilers and road motor vehicles. 

(c) Whoever owns or causes to be used a boiler subject to inspec- 
tion shall report the location of such boilers to the Industrial Acci- 
dent Commission of the State of California on January 1st, or 
within thirty (30) days thereafter, of each year. 

(d) The owner or user of a boiler or boilers herein required to 
be inspected shall, after fourteen (14) days notice, prepare the 
boiler for internal inspection, or hydrostatic pressure test, if neces- 
sary. To prepare a boiler for internal inspection, the water shall 
be drawn off and the boiler thoroughly washed. All manhole and 
handhole covers,* and wash-out plugs in boilers and water column 
connections shall be removed, and the furnace and combustion 
chamber thoroughly cooled and cleaned. Enough of the brickwork 
shall be removed to determine the condition of the boiler, furnace 
or other parts, at each annual inspection. 

The steam gage shall be removed for testing. 

(e) If it is found that steam or hot water is leaking into the 
boiler, the source of such leakage shall be disconnected and so 
drained as to cut out such steam or hot water from the boiler to be 
inspected. 

(/) If the boiler is jacketed so that the longitudinal seams of 
shells, drums or domes can not be seen, and if it can not otherwise be 
determined, enough of the jacketing, setting wall or other covering 
shall be removed so that the size and pitch of the rivets and such 
other data as may be necessary can be determined at first data 
inspection. 

*As a rule, in watertube boilers, it will be sufficient if such as are necessary 
of the two lower rows of tube covers be removed. 



Vlll BOILER SAFETY ORDERS. 

(g) In preparing a boiler for hydrostatic test, the boiler shall be 
filled to the stop valve. If boiler to be tested is connected with 
other boilers that are under steam pressure, such connections shall 
be blanked off unless there be double stop valves on air connecting 
pipes, with an open drain between. 

Order 801. Insurance inspections. 

All boilers subject to periodic inspection of insurance '"companies 
authorized to insure boilers in the State of California shall be 
exempt from regular annual inspection by the Industrial Accident 
Commission on the following conditions : 

(a) The insurance companies' regulations shall conform with 
the herein orders. 

(&) The insurance companies' inspectors who inspect boilers 
operated in this State shall hold certificates of competency issued 
by the Industrial Accident Commission, as hereinafter provided. 

(c) Reports of all inspections shall conform to the requirements 
of this Commission, and shall be made upon the forms provided. 

(d) A copy of all annual reports shall be forwarded to this 
Commission within twenty-one (21) days after the inspection is 
made, on the forms provided. 

(e) Insurance companies whose inspectors hold certificates of 
competency shall immediately report to this Commission the name 
of the owner or operator, and the location of every boiler on which 
insurance has been refused, cancelled or discontinued, giving the 
reasons therefor. 

Order 802. Special inspections. 

(a) Steam boilers within the regular corporate limits of counties 
and cities, which are regularly inspected by an authorized county 
or city inspector, and steam boilers operated or controlled by com r 
panies or corporations which receive regular annual inspections by 
an inspector employed by the said companies or corporations, shall 
be exempt from the regular annual inspections made by this Com- 
mission, on the following conditions: 

1. The boilers shall be installed and equipped with the fittings 

necessary to safety as prescribed by these Orders. 

2. The inspector or inspectors shall hold certificates of com- 

petency issued by the Industrial Accident Commission, or 
be duly authorized as deputy inspectors. 

3. Reports of all annual inspections shall conform to tire re- 

quirements of, and a copy of said reports shall be for- 
warded to this Commission within twenty-one (21) days 
after the inspections are made, on the forms provided. 



BOILER SAFETY ORDERS. IX 

Order 803. Certificate of competency. 

(o) Upon the written request of an employer, certificates of 
competency shall be issued to persons who are employed as pro- 
vided in Section (c), and who pass an examination prescribed by 
the Industrial Accident Commission. Such examination shall de- 
termine the fitness and competency of candidates for said certifi- 
cates* 

(6) A certificate of competency may be revoked for cause at 
any time, but the holder of such certificate of competency shall be 
entitled, upon demand, to a hearing before the Industrial Accident 
Commission before the revocation of said certificate. 

(c) A certificate of competency shall be issued only to a person 
who is, or is to be, employed as inspector only by any county, city, 
corporation or company, and shall be annulled upon the termina- 
tion of his employment by the said city, county, corporation or 
company, by which he was employed at the time of the issuance of 
the certificate. Such certificate may, however, be renewed without 
re-examination within a period of one (1) year, upon proof that 
the applicant has been re-engaged as a boiler inspector. 

1. Any applicant who fails to pass the examination may apply 
for a re-examination at the end of ninety days. Pro- 
vided, however, that a person who has been refused a 
certificate of competency may appeal from such decision 
to the Industrial Accident Commission, who shall grant 
a re-hearing. The applicant shall have the privilege of 
having one representative of the county, city, corpora- 
tion or company by whom he is or is to be employed, 
present during the hearing. 

(d) Upon the request of an employer, the Commission may per- 
mit an employee, after passing the prescribed examination, to act 
as a deputy inspector. Such deputy inspector may inspect and 
issue certificates of inspection for only such types of boilers as 
shall be specified in his permit. Such deputy inspectors' permits 
shall be subject to the same terms of revocation, annullment and 
renewal as specified in (b) and (c) of this Order. 

Order 804. Annual inspection certificate. 

(a) A certificate of inspection upon the forms supplied by the 
Industrial Accident Commission shall be issued by the inspector 
in the employ of the county, city, corporation, or company, stating 
the pressure allowed for one year after an inspection has been made. 

♦Candidates will be examined as to their knowledge of the construction, 
installation, operation, maintenance and repair of steam boilers, and of the rules 
governing boilers in California. 



X BOILER SAFETY ORDERS. 

This certificate shall be kept conspicuously posted under glass in 
the engine or boiler room, and shall at all times be available when 
called for by a deputy of this Commission, or by an inspector 
holding a certificate of competency. 

(6) The pressure allowed as stated in the certificate of inspec- 
tion shall not be in excess of that determined by the Orders for 
boilers installed prior to January 1, 1917. 

Order 805. Stamps and numbers on boilers. 

(a) The owner or user of a steam boiler shall number each boiler 
in some convenient and permanent manner. 

(6) Boilers installed after January 1, 1917, shall be stamped by 
the builder with a serial number, date of manufacture and his 
name, in accordance with the herein Orders. 

(c) Boilers built after January 1, 1917, shall conform with these 
Orders, and before being placed in service, shall be inspected and 
a certificate of inspection issued. 

Order 806. New types of boilers. 

(a) Builders of new types of boilers subject to inspection shall 
forward to the Industrial Accident Commission blue prints and 
specifications of the type for approval. 

Order 807. Safety regulations. 

(a) No boiler shall be operated at a pressure in excess of the 
safe working pressure allowed by the annual inspection certificate, 
which pressure is to be ascertained by means of these Orders. 

Order 808. 

(a) Boilers of twelve (12) horsepower or less, on which the pres- 
sure does not exceed fifteen (15) pounds per square inch, which 
are exempt from annual inspection, shall be fitted with such 
appliances as to insure safety as herein prescribed. 

Order 809. 

(a) Any boiler in this State at the time these Orders take effect 
which does not conform to the herein Orders, may be operated, if 
found safe, after a thorough internal and external inspection, and 
a hydrostatic pressure test, if necessary. 

(&) No new power boiler shall be installed in the State of Cali- 
fornia after these Orders take effect, which was not stamped when 
built by the manufacturer with the American Society of Mechanical 
Engineers Boiler Code stamp, except after a joint inspection by the 



BOILER SAFETY ORDERS. XI 

Industrial Accident Commission and another inspector holding a 
certificate of competency. The lowest factor of safety on boilers 
of this kind shall be six (6), except that all new boilers carried in 
stock in this State on or before January 1, 1917, by dealers or 
private owners, may be installed after these Orders take effect, 
using a factor of safety as stipulated for existing installations, pro- 
vided that they shall be equipped with all the necessary appliances 
to comply with the herein Orders, as laid down for new installations. 
Provided further that new boilers built prior to the date these 
Orders go into effect, under the supervision and to the regulations 
of the Interstate Railroad and/or the Interstate Commerce Com- 
mission, may also be installed and placed in operation under these 
same provisions. 

Order 810. 

(a) Steam boilers shall be equipped with such appliances as will 
insure safety of operation as herein ordered. 

Order 811. 

(a) No person shall remove or tamper with any safety appliance 
prescribed by the herein Orders, and no person shall in any man- 
ner load the safety valve to greater pressure than that allowed by 
the certificate of inspection. 

Order 812. 

(a) In case a defect affecting the safety of a steam boiler is 
discovered, the owner or user of the boiler shall immediately notify 
the inspector issuing the certificate of inspection, but if said boiler 
be not subject to annual inspection, the owner or user shall in that 
case report the defect to the Industrial Accident Commission. The 
boiler shall not again be placed in service until the defect has been 
remedied. 

Order 813. 

(a) All patches on a boiler shell or drum which exceed twenty- 
four (24) inches in length, measured on a line parallel to the 
longitudinal seam, and between the center lines of the extreme 
rivet holes, shall be calculated for safe working pressure from said 
patch seam, the efficiency of which shall be determined in trie usual 
manner. 

The efficiency of the patch seam may then be increased by multi- 
plying said efficiency by a factor which is determined by the 



Xll 



BOILER SAFETY ORDERS. 



angularity of the inclined patch seam to the girth seam, according 
to the following table : 



Angle 


Factor 


Angle 


Factor 


30° 


1.51 


50° 


1.20 


35° 


1.42 


55° 


1.15 


40° 


1.34 


60° 


1.11 


45° 


1.27 


65° 


1.08 



Order 814. 

(a) No cast iron hot water heating boiler shall carry a greater 
pressure, static or from supply main, than that named in the guar- 
antee of the manufacturer, and in no case shall the pressure exceed 
thirty (30) pounds per square inch. 

Order 815. 

(a) Where it is found impossible to definitely determine the age 
of a boiler of lap seam construction, the factor of safety shall be 
not less than five and one-half (5J). 

(b) No pressure on a boiler of lap seam construction shall exceed 
one hundred and sixty-five (165) pounds per square inch. 

Order 816. 

(a) The use of plug cocks so constructed that there is no gland 
or yoke to hold the plug in place will not be allowed. If yokes or 
glands are of the open hole slot type at both ends, they shall have 
said slots effectively closed. 

Order 817. 

(a) Where boiler settings are so designed that gas can accumu- 
late to a dangerous extent, provision must be made for venting 
said gas pockets. 

.(b) All dampers used in connection with oil burning furnaces 
under steam boilers shall be made with, or have suitable openings 
therein to vent the furnace from an accumulation of gas. Suitable 
explosion doors or similar devices will be considered as carrying 
out the provisions of this Order. 

Order 818. 

(a) If there are valves in the connections between water column 
and boiler, at least one steam gage shall be connected directly to 



Note. — It is recommended that if there are valves in the connections between 
the water column and the boiler, such valves should be of straight way outside 
screw and yoke, or rising stem type, and should be set vertically with the stems 
down, and when the boiler is in operation, be locked or sealed open. 



BOILER SAFETY ORDERS. Xlll 

steam space of boiler, with but one cock between said gage and 
boiler. 

Order 819. 

(a) In determining the sizes of safety valves, the following 
table showing the ratio of heating surface to horsepower, shall be 
used. 



Type of boiler 



Water heating 
surface for 

1 horsepower. 
Square feet 



Cylindrical 

Flue 

Firebox tubular 
Return tubular . 

Vertical ... 

Water tube 



Order 820. A. S. M. E. Boiler Code. 

(a) The Boiler Code, Edition of 1914, with Index, of the Ameri- 
can Society of Mechanical Engineers, as copyrighted in 1915, is 
made a part of these Orders with certain changes and additions, 
all of which said changes and additions refer only to Existing 
Installations. 

Order 821. Steam heating boilers [existing and new installa- 
tions]. 
Fittings and Appliances, 
(a) There shall be a stop valve on each steam outlet from the 
boiler, except a safety valve connection. 

(6) When a damper regulator is used, it shall be connected to 
the steam space of the boiler and there shall be a stop valve or stop 
cock in the connecting pipe. 

(c) The main return pipe to a heating boiler (gravity return 
system) shall have a check valve and also a stop valve between the 
said check valve and the boiler. 

When there are two connected boilers with a gravity return 
system, one check valve may be placed on the main return pipe 
and a stop valve on the branch pipe to each boiler. 

(d) Each boiler shall have a feed pipe fitted with a check valve 
and also a stop valve between the check valve and the boiler, the 
feed water to discharge below the lowest safe water line. 

Means must be provided for feeding a boiler against the maxi- 
mum pressure allowed on the boiler. 



XIV 



INDEX. 



INDEX TO BOILER SAFETY ORDERS. 



Page 

Age of boiler unknown xii 

Appliances xi 

A. S. M. E. Boiler Code xiii 

Blow offs. Plug cocks not allowed xii 

Boiler Code of A. S. M. E ; xiii 

Boilers in State when these Orders take effect x 

Boilers not bearing A. S. M. E. Code Stamp x 

Boilers of lap construction, 165 limit pressure xii 

Builder's serial number x 

Boilers, new types of '. x 

Boilers, steam heating xiii 

Boilers, to be numbered x 

Certificate, annual inspection ix 

Certificate, annual inspection, posted under glass ix 

Covering, insulating, to be removed vii 

Certificates of competency, annullment of ix 

Certificates of competency, examination for ix 

Certificates of competency, revocation of ix 

Certificates of competency. Insurance inspectors viii 

Certificates of competency. Deputy inspectors ix 

Damper regulator, valve or cock in xiii 

Dampers to be vented xii 

Defects, serious to be reported - xi 

Deputy inspectors ix 

Examination for certificate of competency ix 

Exemptions from annual inspection vii 

Exemptions to have safety appliances . x 

Feed pipe, stop valve and check valve in xiii 

Gage, steam, removal of vii 

Gage, connected to steam space xii 

Gas pockets in flue or setting xii 

Gravity returns, stop valve and check valve in xiii 

Heating boilers, hot water xi 

Horsepower, ratio of heating surface to xii 

Hydrostatic, preparation for test vii 

Inspection, insurance ■. viii 

Inspection, internal, external vii 

Inspection, leaks to be stopped vii 

Inspection, notice of annual vii 

Inspection, preparation for annual vii 

Interval fourteen months vii 

Insurance, refused, cancelled or discontinued viii 



Order 

815 


Subdi- 
vision 

a 


810 


a 


820 


a 


816 


a 


820 


a 


809 


a 


809 


b 


815 


b 


805 


b 


806 


a 


821 




805 


a 


804 




804 


a 


800 


f 


803 


(1 


803 


a 


803 


I) 


801 


1) 


803 


(1 


821 


b 


817 


b 


812 


a 


803 


d 


803 


a,c,<! 


800 


b 


808 


a 


821 


d 


800 


d 


818 


a 


817 


a 


821 


c 


814 


a 


819 


a 


800 


d, g 


801 




800 


a 


800 





800 


(1 


800 


d 


800 


a 


801 


e 



INDEX. XV 



Inspections, special 

Insurance inspectors, annual reports 

Insurance inspectors, reports to conform — 
Insurance regulations to conform 

Jacket i to be removed 



Pressure allowed 

Report, annual, of location 

Safety regulations 

Safe working pressure 

Safety valves, tampering with or removing. 

Valves, double stop, on connecting pipes 

Valves, stop, on steam pipes 



Page 
viii 


Order 

802 


Subdi- 
vision 


viii 


801 


d 


viii 


801 


c 


viii 


801 


a 


vii 


800 


f 


xi 


813 


a 


X 


804 


b 


vii 


800 


c 


X 


SOT 




X 


807 


a 


xi 


811 


a 


viii 


800 


g 


xiii 


821 


a 



THE AMERICAN SOCIETY OF MECHANICAL 
ENGINEERS 

REPORT 

OF THE COMMITTEE 

TO FORMULATE STANDARD SPECIFICATIONS 

FOR THE 

CONSTRUCTION OF STEAM BOILERS AND OTHER 

PRESSURE VESSELS AND FOR THEIR 

CARE IN SERVICE 



KNOWN AS 



THE BOILER CODE COMMITTEE 




RULES FOR THE 

CONSTRUCTION OF STATIONARY BOILERS AND 

Ff)R ALLOWABLE WORKING PRESSURES 

Edition of 1914 with Index 

Copyright, 1915, by 

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS 



To the Council of The American Society of 
Mechanical Engineers 

Gentlemen: Your Committee appointed September 15th, 1911 to 
"Formulate Standard .Specifications for the Construction of Steam 
Boilers and Other Pressure Vessels and for Care of ,Same in Service" 
respectfully submits its final report on Eules for the construction and 
allowable working pressures of stationary boilers, which forms a por- 
tion of the task assigned to it. 

The primary object of these Eules is to secure safe boilers. The 
interests of boiler users and manufacturers have been carefully con- 
sidered and the requirements made such that they will not entail 
undue hardship by departing too widely from present practice. 

Your Committee recommends that you appoint a permanent com- 
mittee to make such revisions as may be found desirable in these Eules, 
and to modify them as the state of the art advances, and that such 
committee should hold meetings at least once in two years at which 
all interested parties may be heard. 

Yours truly, 

John A. Stevens, Chairman 
Wm. H. Boehm 
Kolla C. Carpenter 
Eichard Hammond 
Chas. L. Huston 
Edward F. Miller 
H. C. Meinholtz* 
E. I). Meier* 
Deceased* 



COMMITTEE 



Submitted to the Council of The American Society op Mechanical Engineers, Feb- 
ruary 13, 1915. 



Your Committee secured the assistance of the following Engi- 
neers as an Advisory Committee, representing various phases of the 
design, installation and operation of boilers and the Rules were un- 
animously approved by them. 

F. II. Clark, Railroad Sub-Committee, The American Society of Mechanical 
Engineers. 

F. W. Dean, Consulting Engineers. 

Tnos. E. Durban, Boiler Manufacturers' Association, Uniform Specifica- 
tions Committee, for all types of boilers. 

Carl Ferrari, National Tubular Boiler Manufacturers' Association. 

Elbert C. Fisher, Scotch marine and other types of boilers. 

Arthur M. Greene, Jr., Engineering Education. 

Chas. E. Gortox, Steel heating boilers. 

A. L. Humphrey, Railroad Sub-Committee, The American Society of Me- 
chanical Engineers. 

D. S. Jacobus, Water-tube boilers. 

S. F. Jeter, Boiler insurance. 

Wm. F. Kiesel, Jr., Railroad Sub-Committee, The American Society of Me- 
chanical Engineers. 

W. F. MacGregor, National Association of Thresher Manufacturers. 

M. F. Moore, Steel heating boilers. 

I. E. Moultrop, Boiler users. 

Richard D. Reed, National Boiler & Radiator Manufacturers'' Association. 

H. G. Stott, Boiler users. 

H. H. Yaughan, Railroad Sub-Committee, The American (Society of Me- 
chanical Engineers. 

C. W. Obert, Secretary to Committee. 



CONTENTS 

Part I. New Installations pages 

Section 1. Power Boilers 7-80 

Section 2. Heating Boilers 81-87 

Part II. Existing Installations . . . . . , . . t . . 89-93 

Appendix 95—114 

Index 115-147 



RULES FOR THE 

CONSTRUCTION OF STATIONARY BOILERS 

AND FOR ALLOWABLE WORKING 

PRESSURES 



The Rules are divided into two parts: 

T> \ nm t v x • j, ii x- f Section I, Power Boilers. 

rAK T 1 applies to new installations. { ^ .. TT TT . . ■._ 

I beetion 11, Heating Boilers. 

PART II applies to existing installations. 



PART I NEW INSTALLATIONS 

SECTION I 
POWER BOILERS 

(Selection" oe Materials 



1 Specifications are given in these Rules for the important ma- 
terials used in the construction of boilers, and where given, the ma- 
terials shall conform thereto. 

2 Steel plates for any part of a boiler when exposed to the fire 
or products of combustion, and under pressure, shall be of firebox 
quality as designated in the Specifications for Boiler Plate Steel. 

3 Steel plates for any part of a boiler, where firebox quality is 
Dot specified, when under pressure, shall be of firebox or flange quality 
as designated in the Specifications for Boiler Plate Steel. 

4: Braces when welded, shall be of wrought-iron of the quality 
designated in the Specifications for Refined "Wrought-iron Bars. 

5 Manhole and handhole covers and other parts subjected to pres- 
sure and braces and lugs, when made of steel plate, shall be of firebox 
or flange quality as designated in the Specifications for Boiler Plate 
Steel. 

6 Steel bars for braces and for other boiler parts, except as other- 
wise specified herein, shall be of the quality designated in the Specifi- 
cations for Steel Bars. 

7 Staybolts shall be of iron or steel of the quality designated in 
the Specifications for Staybolt Iron or in the Specifications for Stay- 
bolt Steel. 



8 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

8 Rivets shall be of steel or iron of the quality designated in the 
Specifications for Boiler Rivet Steel or in the .Specifications for Boiler 
Rivet Iron. 

9 Cross pipes connecting the steam and water drums of water- 
tube boilers, headers and cross boxes and all pressure parts of the boiler 
proper over 2-in. pipe size, or equivalent cross-sectional area, shall be 
of wrought steel, or cast steel of Class B grade, as designated in the 
Specifications for Steel Castings, when the maximum allowable work- 
ing pressure exceeds 160 lb. per sq. in. 

10 Mud drums of boilers used for other than heating purposes 
shall be of wrought steel, or cast steel of Class B grade, as designated 
in the iSpecifications for Steel Castings. 

11 Pressure parts of superheaters, separately fired or attached to 
stationary boilers, unless of the locomotive type, shall be of wrought 
steel, or cast steel of Class B grade, as designated in the Specifications 
for Steel Castings. 

12 Cast iron shall not be used for boiler and superheater mount- 
ings, such as nozzles, connecting pipes, fittings, valves and their bon- 
nets, for steam temperatures of over 450 deg. fahr. 

13 Water-leg and door-frame rings of vertical fire-tube boilers 
36 in. or over in diameter, and of locomotive and other type boilers, 
shall be of wrought iron or steel, or cast steel of Class B grade, as 
designated in the Specifications for Steel Castings. The G or other 
flanged construction may be used as a substitute in any case. 



Ultimate Strength of Material used in Computing Joints 

14 Tensile Strength of Steel Plate. The tensile strength used 
in the computations for steel plates shall be that stamped on the plates 
as herein provided, which is the minimum of the stipulated range, or 
55,000 lbs. per sq. in. for all steel plates, except for special grades 
having a lower tensile strength. 

15 Crushing Strength of Steel Plate. The resistance to crush- 
ing of steel plate shall be taken at 95,000 lb. per sq. in. of cross-sec- 
tional area. 

16 Strength of Rivets in Shear. In computing the ultimate 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 9 

strength of rivets in shear, the following values in pounds per square 
inch of the cross-sectional area of the rivet shank shall be used: 

Iron rivets in single shear 38,000 

Iron rivets in double shear 76,000 

Steel rivets in single shear 44,000 

Steel rivets in double shear 88,000 

The cross-sectional area used in the computations shall be that of 
the rivet shank after driving. 

Minimum Thicknesses of Plates and Tubes 

17 Thickness of Plates. The minimum thickness of any boiler 
plate under pressure shall be 14 in. 

18 The minimum thicknesses of shell plates, and dome plates 
after flanging, shall be as follows : 

When the Diameter of Shell is 

36 In. or Under Over 36 In. to 54 In. Over 54 In. to 72 In. Over 72 In. 
V± in. iVin. % in. y 2 in. 

19 The minimum thicknesses of butt straps shall be as given in 
Table 1. 

TABLE 1 MINIMUM THICKNESSES OF BUTT STRAPS 



Thickness of 


Minimum Thickness 


Thickness of 


Minimum Thickness 


Shell Plates, 


of Butt Straps, 


Shell Plates, 


of Butt Straps, 


In. 


In. 


In. 


In. 


M 


y± 


» 


A 


A 


% 


A 


T6 


A 


H 


« 


H 


H 


X 


H 


H 


% 


A 


y% 


% 


H 


A 


1 


% 


A 


% 


1H 


% 


H 


% 


IX 


% 


H 


A 







20 The minimum thicknesses of tube sheets for horizontal return 
tubular boile-rs, shall be as follows: 



42 In. or Under 

% in. 



When the Diameter of Tube Sheet is 

Over 42 In. to 54 In. 
4s in. 



Over 54 In. to 72 In. 
% in. 



Over 72 In. 
Tff in. 



10 RErORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

21 Tubes for Water-Tube Boilers. The minimum thicknesses 
of tubes used in water-tube boilers measured by Birmingham wire 
gage, for maximum allowable working pressures not exceeding 165 lb. 
per sq. in., shall be as follows : 

Diameters less than 3 in . No. 12 B.W.G. 

Diameter 3 in. or over, but less than 4 in No. 11 B.W.G. 

Diameter 4 in. or over, but less than 5 in No. 10 B.W.G. 

Diameter 5 in No. 9 B.W.G. 

The above thicknesses shall be increased for maximum allowable 
working pressures higher than 165 lb. per sq. in. as follows : 

Over 165 lb. but not exceeding 235 lb 1 gage 

Over 235 lb. but not exceeding 285 lb 2 gages 

Over 285 lb. but not exceeding 400 lb 3 gages 

Tubes over -1-in . diameter shall not be used for maximum allowable 
working pressures above 285 lb. per sq. in. 

22 Tubes for Fire-Tube Boilers. The minimum thicknesses of 
tubes used in fire tube boilers measured by Birmingham wire gage, for 
maximum allowable working pressures not exceeding 175 lb. per sq. 
in., shall be as follows : 

Diameters less than 2% in No. 13 B.W.G. 

Diameter 2% in. or over, but less than 3 x /4 in. . . No. 12 B.W.G. 

Diameter 3*4 in. or over, but less than 4 in No. 11 B.W.G. 

Diameter 4 in. or over, but less than 5 in No. 10 B.W.G. 

Diameter 5 in No. 9 B.W.G. 

For higher maximum allowable working pressures than given above 
the thicknesses shall be increased one gage. 



NEW INSTALLATIONS, TART I, SECTION I, POWER BOILERS 11 

SPECIFICATIONS FOR BOILER PLATE STEEL 

THESE SPECIFICATIONS 1 ARE SIMILAR TO THOSE OF THE AMER- 
ICAN SOCIETY FOR TESTING MATERIALS, SERIAL DESIGNATION A 30-14. 

23 Grades. These specifications cover two grades of steel for 
boilers, namely : flange and firebox. 

I Manufacture 

24 Process. The steel shall be made by the open-hearth process. 

II Chemical Pboperties and Tests 

25 Chemical Composition. The steel shall conform to the fol- 
lowing requirements as to chemical composition : 



FLANGE FIREBOX 

Carbon Plates % in. thick and under. . 0.12 — 0.25 per cent 

Plates over % in. thick 0.12 — 0.30 per cent 

Manganese 0.30 — 0.60 per cent 0.30 — 0.50 per cent 

j Acid Not over 0.05 per cent Not over 0.04 percent 

( Basic Not over 0.04 per cent Not over 0.035 per cent 

Sulphur Not over 0.05 per cent Not over 0.04 per cent 

Copper Not over 0.C5 per cent 



26 Ladle Analyses. An analysis shall be made by the manu- 
facturer from a test ingot taken during the pouring of each melt, a 
copy of which shall be given to the purchaser or his representative. 
This analysis shall conform to the requirements specified in Par. 25. 

27 Cliocl- Analyses. Analyses may be made by the purchaser 
from a broken tension test specimen representing each plate as rolled, 
which shall conform to the requirements specified in Par. 25. 



""Approved and recommended in its modified form, October 9, 1914, by the 
Association of American Steel Manufacturers, the American Boiler Manu- 
facturers' Association, the National Tubular Boiler Manufacturers' Associa- 
tion, the National Association of Thresher Manufacturers and the representa- 
tives present of leading Water Tube Boiler Manufacturers, with whom the 
Boiler Code Committee was in conference on September 16, 1914, and by whom 
further modifications were afterwards offered. 



12 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

Ill Physical Pkoperties and Tests 

28 Tension Tests, a The material shall conform to the follow- 
ing requirements as to tensile properties : 

FLANGE FIREBOX 

Tensile strength, lb. per sq. in 55,000—65,000 55,000—63,000 

Yield point, min., lb. per sq. in 0.5 tens. str. 0.5 tens. str. 

1,500,000 1,500,000 



Elongation in 8-in., min., per cent (See Par. 29) 



Tens. str. Tens. str. 



b If desired steel of lower tensile strength than the above may be 
used in an entire boiler, or part thereof, the desired tensile limits to 
be specified, having a range of 10,000 lb. per sq. in. for flange or 8000 
lb. per sq. in. for firebox, the steel to conform in all respects to the 
other corresponding requirements herein specified, and to be stamped 
with the minimum tensile strength of the stipulated range. 

c The yield point shall be determined by the drop of the beam 
of the testing machine. 

29 Modifications in Elongation, a For material over % in. in 
thickness, a deduction of 0.5 from the percentages of elongation 
specified in Par. 28a, shall be made for each increase of % in. in 
thickness above % in., to a minimum of 20 per cent. 

b For material *4 *m or under in thickness, the elongation shall 
be measured on a gage length of 24 times the thickness of the specimen. 

30 Bend Tests, a Cold-bend Tests — The test specimen shall 
bend cold through 180 cleg, without cracking on the outside of the 
bent portion, as follows : For material 1 in. or under in thickness, flat 
on itself; and for material over 1 in. in thickness, around a pin the 
diameter of which is equal to the thickness of the specimen. 

b Quench-bend Tests — The test specimen, when heated to a light 
cherry red as seen in the dark (not less than 1200 deg. fahr.), and 
quenched at once in water the temperature of which is between 80 deg. 
and 90 deg. fahr., shall bend through 180 deg. without cracking on tho 
outside of the bent portion, as follows : For material 1 in. or under in 
thickness, flat on itself; and for material over 1 in. in thickness, 
around a pin the diameter of which is equal to the thickness of the 
specimen. 

31 Homogeneity Tests. For firebox steel, a sample taken from 
a broken tension test specimen shall not show any single seam or 
cavity more than ^4 in. long, in either of the three fractures obtained 
in the test for homogeneity, which shall be made as follows : 



NEW INSTALLATIONS, PART I, SECTION 1, POWER BOILERS 13 

The specimen shall be either nicked with a chisel or grooved on 
a machine, transversely, about 1/16 in. deep, in three places about 
2 in. apart. The first groove shall be made 2 in. from the square end ; 
each succeeding groove shall be made on the opposite side from the 
preceding one. The specimen shall then be firmly held in a vise, with 
the first groove about ^4 in. above the jaws, and the projecting end 
broken off by light blows of a hammer, the bending being away from 
the groove. The specimen shall be broken at the other two grooves in 
the same manner. The object of this test is to open and render visible 
to the eye any seams due to failure to weld or to interposed foreign 
matter, or any cavities due to gas bubbles in the ingot. One side of 
each fracture shall be examined and the length cf the seams and 
cavities determined, a pocket lens being used if necessary. 

32 Test Specimens. Tension and bend test specimens shall be 
taken from the finished rolled material. They shall be of the full 



K ___ ;.j'„_ „ ,* K %fl&%lffi h 

UlJ . L 



■>|i'|</vU/M 



Fig. 1 Standard Form of Test Specimen Required for all Tension Tests 

of Plate Material 

thickness of material as rolled, and shall be machined to the form and 
dimensions shown in Fig. 1 ; except that bend test specimens may be 
machined with both edges parallel. 

33 Number of Tests, a One tension, one cold-bend, and one 
quench-bend test shall be made from each plate as rolled. 

b If any test specimen shows defective machining or develops 
flaws, it nmy be discarded and another specimen substituted. 

c If the percentage of elongation of any tension test specimen is 
less than that specified in Pars. 28 and 29, and any part of the fracture 
is outside the middle third of the gaged length, as indicated by the 
scribe scratches marked on the specimen before testing, a retest shall 
be allowed. 

IV Permissible Variation in Gage 

34 Permissible Variation. The thickness of each plate shall not 
vary under the gage specified more than 0.01 in. The overweight 



14 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

limits are considered a matter of contract between the steel manu- 
facturer and the boiler builder. 

V Finish 

35 Finish. The finished material shall be free from injurious 
defects and shall have a workmanlike finish. 

VI Marking 

36 Marking, a Each shell plate shall be legibly stamped by 
the manufacturer with the melt or slab number, name of manu- 
facturer, grade and the minimum tensile strength of the stipulated 
range as specified in Par. 28, in three places, two of which shall be 
located at diagonal corners about 12 in. from the edge and one about 
the center of the plate, or at a point selected and designated by the 
purchaser so that the stamp shall be plainly visible when the boiler is 
completed. 

o Each head shall be legibly stamped by the manufacturer in 
two places, about 12 in. from the edge, with the melt or slab number, 
name of manufacturer, grade, and the minimum tensile strength 
of the stipulated range as specified in Par. 28, in such manner that 
the stamp is plainly visible when the boiler is completed. 

c Each butt strap shall be legibly stamped by the manufacturer 
in two places on the center line about 12 in. from the ends with the 
melt or slab number, name of manufacturer, grade, and the minimum 
tensile strength of the stipulated range as specified in Par. ,28. 

d The melt or slab number shall be legibly stamped on each test 
specimen. 

YIT Inspection and Rejection 

37 Inspection. The inspector representing the purchaser shall 
have free entry, at ail times while work on the contract of the pur- 
chaser is being performed, to all parts of the manufacturer's works 
which concern the manufacture of the material ordered. The manu- 
facturer shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the material is being furnished in accordance with 
these specifications. All tests (except check analyses) and inspection 
shall be made at the place of manufacture prior to shipment, unless 
otherwise specified, and shall be so conducted as not to interfere un- 
necessarily with the operation of the works. 



NEW INSTALLATIONS, PART I, SECTION I, TOWER BOILERS 15 

38 Rejection, a Unless otherwise specified, any rejection based 
on tests made in accordance with Par. ,27 shall be reported within five 
working days from the receipt of samples. 

b Material which shows injurious defects subsequent to its ac- 
ceptance at the manufacturer's works will be rejected, and the manu- 
facturer shall be notified. 

39 Rehearing. Samples tested in accordance with Par. 27, which 
represent rejected material, shall be preserved for two weeks from the 
date of the test report. In case of dissatisfaction with the results of 
the tests, the manufacturer may make claim for a rehearing within 
that time. 



SPECIFICATIONS FOR BOILER RIVET STEEL 

THESE SPECIFICATIONS ARE SUBSTANTIALLY THE SAME AS THOSE 
OF THE AMERICAN SOCIETY FOR TESTING MATERIALS, SERIAL DESIG- 
NATION A 31-14. 

A Requirements for Rolled Bars 

I Manufacture 

40 Process. The steel shall be made by the open-hearth process. 

II Chemical Properties and Tests 

41 Chemical Composition. The steel shall conform to the fol- 
lowing requirements as to chemical composition : 

Manganese 0.30-0.50 per cent 

Phosphorus not over 0.04 per cent 

Sulphur not over 0.045 per cent 

42 Ladle Analyses. An analysis to determine the percentages 
of carbon, manganese, phosphorus and sulphur shall be made by the 
manufacturer from a test ingot taken during the pouring of each melt, 
a copy of which shall be given to the purchaser or his representative. 
This analysis shall conform to the requirements specified in Par. 41. 

43 Check Analyses. Analyses may be made by the purchaser 
from finished bars, representing each melt, which shall conform to the 
requirements specified in Par. 41. 



16 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E, 

III Physical Properties and Tests 

44 Tension Tests, a The bars shall conform to the following 
requirements as to tensile properties : 

Tensile strength, lb. per sq. in . . 45,000-55,000 

Yield point, min., lb. per sq. in 0.5 tens. str. 

Elongation in 8 in., min., per cent ' ? 

but need not exceed 30 per cent. Tens. str. 

o The yield point shall be determined by the drop of the beam of 
the testing machine. 

45 Bend Tests, a Cold-bend Tests — The test specimen shall 
bend cold through 180 deg. flat on itself without cracking on the out- 
side of the bent portion. 

b Quench-bend Tests — The test specimen, when heated to a light 
cherry red as seen in the dark (not less than 1200 deg. fahr.), and 
quenched at once in water the temperature of which is between 80 deg. 
and 90 deg. fahr., shall bend through 180 deg. flat on itself without 
cracking on the outside of the bent portion. 

46 Test Specimens. Tension and bend test specimens shall be 
of the full-size section of bars as rolled. 

47 Nnmber of Tests, a Two tension, two cold-bend, and two 
quench-bend tests shall be made from each melt, each of which shall 
conform to the requirements specified. 

b If any test specimen develops flaws, it may be discarded and 
another specimen substituted. 

c If the percentage of elongation of any tension test specimen 
is less than that specified in Par. 44 and any part of the fracture is 
outside the middle third of the gaged length, as indicated by scribe 
scratches marked on the specimen before testing, a retest shall be 
allowed. 

48 Permissible Variations in Gage. The gage of each bar shall 
not vary more than 0.01 in. from that specified. 

V Workmanship and Finish 

49 Workmanship. The finished bars shall be circular within 
0.01 in. 

50 Finish. The finished bars shall be free from injurious de- 
fects and shall have a workmanlike finish. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 17 

VI Marking 

51 Marling. Eivet bars shall, when loaded for shipment, be 
properly separated and marked witli tlie name or brand of the manu- 
facturer and the melt number for identification. The melt number 
shall be legibly marked on each test specimen. 

VII Inspection and Eejection 

52 Inspection. The inspector representing the purchaser shall 
have free entry, at all times while work on the contract of the pur- 
chaser is being performed, to all parts of the manufacturer's works 
which concern the manufacture of the bars ordered. The manu- 
facturer shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the bars are being furnished in accordance with 
these specifications. All tests (except check analyses) and inspection 
shall be made at the place of manufacture prior to shipment, unless 
otherwise specified, and shall be so conducted as not to interfere un- 
necessarily with the operation of the works. 

5,3 Rejection, a Unless otherwise specified, any rejection based 
on tests made in accordance with Par. 43 shall be reported within five 
working days from the receipt of samples. 

b Bars which show injurious defects subsequent to their ac- 
ceptance at the manufacturer's works will be rejected, and the manu- 
facturer shall be notified. 

54 Rehearing. .Samples tested in accordance with Par. 43, which 
represent rejected bars, shall be preserved for two weeks fr®m the 
date of the test report. In case of dissatisfaction with the results of 
the tests, the manufacturer may make claim for a rehearing within 
that time. 

B Eequirements for Rivets 

I Physical Properties and Tests 

55 Tension Tests. The rivets, when tested, shall conform to the 
requirements as to tensile properties specified in Par. 44, except that 
the elongation shall be measured on a gaged length not less than four 
times the diameter of the rivet. 

56 Bend Tests. The rivet shank shall bend cold through 180 
deg. flat on itself, as shown in Fig. 2, without cracking on the outside 
of the bent portion. 



18 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



57 Flattening Tests. The rivet head shall flatten, while hot, to 
a diameter 2V2 times the diameter of the shank, as shown in Fig. 3, 
without cracking at the edges. 

58 Number of Tests, a When specified, one tension test shall 
be made from each size in each lot of rivets offered for inspection. 

b Three bend and three flattening tests shall be made from each 
size in each lot of rivets offered for inspection, each of which shall con- 
form to the requirements specified. 



II Workmanship and Finish 

59 Workmanship. The rivets shall be true to form, concentric, 
and shall be made in a workmanlike manner. 

60 Finish. The finished rivets shall be free from injurious de- 
fects. 





Fig. 2 The Bend 
Test for Eivets 



Fig. 3 The Flat- 
tening Test for 
Eivets 



III Inspection and Rejection 



6/1 Inspection. The inspector representing the purchaser shall 
have free entry, at all times while work on the contract of the pur- 
chaser is being performed, to all parts of the manufacturer's works 
which concern the manufacture of the rivets ordered. The manu- 
facturer shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the rivets are being furnished in accordance with 
these specifications. All tests and inspection shall be made at the 
place of manufacture prior to shipment, unless otherwise specified, 
and shall be so conducted as not to interfere unnecessarily with the 
operation of the works. 

62 Rejection. Eivets which show injurious defects subsequent 
to their acceptance at the manufacturer's works will be rejected, and 
the manufacturer shall be notified. 



NEW INSTALLATIONS, TART I. SECTION I, POWER BOILERS 19 

SPECIFICATIONS FOR STAY BOLT STEEL 

REQUIREMENTS FOR ROLLED BARS 

63 Steel for staybolts shall conform to the requirements for 
Boiler Rivet Steel specified in Pars. 10 to 62, except that the tensile 
properties shall be as follows: 

Tensile strength, lb. per sq. in. . 50,000-60,000 

Yield point, min., lb. per sq. in 0.5 tens. str. 

1,500,000 
Elongation in 8 in., min., per cent ■ 

Tens. str. 

Also with the exception that the permissible variations in gage shall 
be as follows : 

Permissible Variations in Gage. The bars shall be truly round 
within 0.01 in. and shall not vary more than 0.005 in. above, or 
than 0.01 in. below the specified size. 



more 



SPECIFICATIONS FOR STEEL BARS 

THESE SPECIFICATIONS ARE ABSTRACTED FROM THOSE FOR STEEE 



FOR BRIDGES OF THE AMERICAN SOCIETY FOR TESTING MATERIALS, 
SERIAL DESIGNATION A 7-14. 

I Manufacture 
61 Process. The steel shall be made by the open-hearth process. 

II Chemical Properties and Tests 

65 Chemical Composition. The steel shall conform to the fol- 
lowing requirements as to chemical composition : 

C Acid : not over 0.06 per cent 

Phosphorus | Bas . c nQt over 0>04 per eent 

Sulphur not over 0.05 per cent 

66 Ladle Analysis. An analysis to determine the percentages of 
carbon, manganese, phosphorus and sulphur shall be made by the 
manufacturer from a test ingot taken during the pouring of each 
melt, a copy of which shall be given to the purchaser or his representa- 
tive. This analysis shall conform to the requirements specified in 
Par. 65. 



20 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

Ill Physical Properties and Tests 

67 Tension Tests, a The material shall conform to the follow- 
ing requirements as to tensile properties : 

Tensile strength, lb. per sq. in 55,000-65,000 

Yield point, min., per sq. in 0.5 tens. str. 

1,500,000 
Elongation in 8 in., min., per cent* « 

Tens. str. 

Elongation in 2 in., min., per cent 22 

*See Par. 68. 

o The yield point shall be determined by the drop of the beam of 
the testing machine. 

68 Modifications in Elongation, a For bars over % m - m 
thickness or diameter a deduction of 1 from the percentage of elonga- 
tion in 8 in. specified in Par. 67, shall be made for each increase of % 
in. in thickness or diameter above % in., to a minimum of 18 per cent. 

o For bars under 5/16 in. in thickness or diameter a deduction 
of 2.5 from the percentage of elongation in 8 in. specified in Par. 67, 
shall be made for each decrease of 1/16 in. in thickness or diameter 
below 5/16 in. 

69 Bend Tests, a The test specimen shall bend cold through 
180 deg. without cracking on the outside of the bent portion, as fol- 
lows: For material % in. or under in thickness or diameter flat on 
itself; for material over % in. to and including iy± in. in thickness or 
diameter around a pin the diameter of which is equal to the thickness 
or diameter of the specimen ; and for material over 114 in. in thickness 
or diameter around a pin the diameter of which is equal to twice the 
thickness or diameter of the specimen. 

o The test specimen for bars over iy 2 in. in thickness or diameter 
when prepared as specified in Par. 70, shall bend cold through 180 
deg. around a 1-in. pin without cracking on the outside of the bent 
portion. 

70 Test Specimens, a Tension and bend test specimens except 
as specified in b, shall be of the full thickness of material as rolled. 
They may be machined to the form and dimensions shown in Fig. 1, 
or may have both edges parallel. 

b Tension test specimens for bars over iy 2 in. in thickness or 
diameter may be of the form and dimensions shown in Fie:. 4. Bend 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 21 

test specimens may be 1 by V2 m - m section. The axis of the specimen 
shall be located at any point midway between the center and surface 
and shall be parallel to the axis of the bar. 

71 Number of Tests, a One tension and one bend test shall be 
made from each melt; except that if material from one melt differs 
% in. or more in thickness, one tension and one bend test shall be 
made from both the thickest and the thinnest material rolled. 

b If any test specimen shows defective machining or develops 
flaws, it may be discarded and another specimen substituted. 

c If the percentage of elongation of any tension test specimen is 
less than that specified in Par. 67, and any part of the fracture is 
more than % in. from the center of the gage length of a 2-in. specimen 
or is outside the middle third of the gage length of an 8-in. specimen, 
as indicated by scribe scratches marked on the specimen before testing, 
a retest shall be allowed. 

IV Permissible Variations in Gage 

72 Permissible Variation. The thickness or cross-section of each 
piece of steel shall not vary under that specified more than 2.5 per 
cent. (Xote: Overweight variation is a matter of contract between 
the steel manufacturer and boiler builder.) 

V Finish 

73 Finish. The finished material shall be free from injurious 
defects and shall have a workmanlike finish. 

VI Marking 

74 Marling. Bars shall, when loaded for shipment, be properly 
separated and marked with the name or brand of the manufacturer 
and melt number for identification. The melt number shall be legibly 
marked on each test specimen. 

VII Inspection and Rejection 

75 Inspection. The inspector representing the purchaser shall 
have free entry, at all times while work on the contract of the pur- 
chaser is being performed, to all parts of the manufacturer's works 



22 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

which concern the manufacture of the material ordered. The manu- 
facturer shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the material is being furnished in accordance with 
these specifications. All tests and inspection shall be made at the place 
of manufacture prior to shipment, unless otherwise specified, and shall 
be so conducted as not to interfere unnecessarily with the operation of 
the works. 

76 Rejection. Material which shows injurious defects subsequent 
to its acceptance at the manufacturer's works will be rejected, and the 
manufacturer shall be notified. • • 



SPECIFICATIONS FOR STEEL CASTINGS 

THESE SPECIFICATIONS ARE ABSTRACTED FROM THOSE FOR STEEL 
CASTINGS OF THE AMERICAN SOCIETY FOR TESTING MATERIALS, 
SERIAL DESIGNATION A 27-14. 

77 Classes. These specifications cover two classes of castings, 
namely : 

Class A, ordinary castings for which no physical requirements 

are specified. 
Class B, castings for which physical requirements are specified. 

These are of three grades: hard, medium, and soft. 

78 Patterns, a Patterns shall be made so that sufficient finish 
is allowed to provide for all variations in shrinkage. 

o Patterns shall be painted three colors to represent metal, cores, 
and finished surfaces. It is 'recommended that core prints shall be 
painted black and finished surfaces red. 

79 Basts of Purchase. The purchaser shall indicate his intention 
to substitute the test to destruction specified in Par. 87, for the tension 
and bend tests, and shall designate the patterns from which castings 
for this test shall be made. 

I Manufacture 

80 Process. The steel may be made by the open-hearth, crucible, 
or any other process approved by the purchaser. 

81 Heat 'Treatment, a Class A castings need not be annealed 
unless so specified. 

b Class B castings shall be allowed to become cold. They shall 
then be uniformly reheated to the proper temperature to refine the 



NEW INSTALLATIONS, PART I, SECTION I, TOWER BOILERS 23 

grain (a group thus reheated heing known as an "annealing charge"), 
and allowed to cool uniformly and slowly. If, in the opinion of the 
purchaser or his representative, a casting is not properly annealed, he 
may at his option require the casting to he re-annealed. 

II Chemical Propebties and Tests 

82 Chemical Composition. The castings shall conform to the 
following requirements as to chemical composition : 

Class A Class B 

Carbon not over 0.30 per cent 

Phosphorus not over 0.06 per cent not over 0.05 per cent 

Sulphur not over 0.05 per cent 

83 Ladle Analyses. An analysis to determine the percentages of 
carbon, manganese, phosphorus and sulphur shall be made by the man- 
ufacturer from a test ingot taken during the pouring of each melt, a 
copy of which shall be given to the purchaser or his representative. 
This analysis shall conform to the requirements specified in Par. 82. 
Drillings for analysis shall be taken not less than 14 in. beneath the 
surface of the test ingot. 

84 Chech Analyses, a Analyses of Class A castings may be 
made by the purchaser, in which case an excess of 20 per cent above the 
requirement as to phosphorus specified in Par. 8*2, shall be allowed. 
Drillings for analysis shall be taken not less than 14 in beneath the 
surface. 

Analyses of Class B castings may be made by the purchaser 
from a broken tension or bend test specimen, in which case an excess 
of 20 per cent above the requirements as to phosphorus and sulphur 
specified in Par. 82, shall be allowed. Drillings for analysis shall be 
taken not less than ^4 in. beneath the surface. 



Ill Physical Properties and Tests 
(For Class B Castings only.) 

85 Tension Tests, a The castings shall conform to the follow- 
ing minimum requirements as to tensile properties: 



24 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

Hard Medium Soft 

Tensile strength, lb. per sq. in 80,000 70,000 C0,000 

Yield point, lb. per sq. in 36,000 31,500 27,000 

Elongation in 2 in., per cent 15 18 22 

Keduetion of area, per cent 20 25 30 

b The yield -poiut shall be determined by the drop of the beam 
of the testing machine. 

&6 Bend Tests, a The test specimen for soft castings shall bend 
cold through 1,20 cleg., and for medium castings through 90 deg., 
around a 1-in. pin, without cracking on the outside of the bent portion. 

b Hard castings shall not be subject to bend test requirements. 

87 Alternative Tests to Destruction. In the case of small or un- 
important castings, a test to destruction on three castings from a lot 
may be substituted for the tension and bend tests. This test shall show 
the material to be ductile, free from injurious defects, and suitable 
for the purpose intended. A lot shall consist of all castings from one 
melt, in the same annealing charge. 

88 Test Specimens, a Sufficient test bars, from which the test 
specimens required in Par. 89, may be selected, shall be attached to 
castings weighing 500 lb. or over, when the design of the castings will 
permit. If the castings weigh less than 500 lb., or are of such a design 
that test bars cannot be attached, favo test bars shall be cast to represent 
each melt; or the quality of the castings shall be determined by tests 
to destruction as specified in Par. 87. All test bars shall be annealed 
with the castings they represent. 

b The manufacturer and purchaser shall agree whether test bars 
can be attached to castings, on the location of the bars on the castings, 
on the castings to which bars are to be attached, and on the method 
of casting unattached bars. 

c Tension test specimens shall be of the form and dimensions 
shown in Fig. 4. Bend test specimens shall be machined to 1 by % 
in. in section with corners rounded to a radius not over 1/16 in. 

89 Number of Tests, a One tension and one bend test shall be 
made from each annealing charge. If more than one melt is repre- 
sented in an annealing charge, one tension and one bend test shall be 
made from each melt. 

b If any test specimen shows defective machining or develops 
flaws, it may be discarded; in which case the manufacturer and the 
purchaser or his representative shall agree upon the selection of an- 
other specimen in its stead. 



NEW INSTALLATIONS, PART I, SECTION I, TOWER BOILERS '. 

c If the percentage of elongation of any tension test specimen : 
less than that specified in Tar. 85, and any part of the fracture ii 
more than 3 ; L in. from the center of the gaged length, as indicated by 
scribe scratches marked on the specimen before testing, a retest shall 
be allowed. 

IV Workmanship and Finish 

90 Workmanship. The castings shall substantially conform to 
the sizes and shapes of the patterns, and shall be made in a workman- 
like manner. 

91 Finish, a The castings shall be free from injurious defects. 
b Minor defects which do not impair the strength of the castings 

may, with the approval of the purchaser or his representative, be 




Fig. 4 Standard Form of Test Specimen Bequired for all Tension Tests 
of Steel Casting Material 



welded by an approved process. The defects shall first be cleaned out 
to solid metal; and after welding, the castings shall be annealed, if 
specified by the purchaser or his representative. 

c The castings offered for inspection shall not be painted or 
covered with any substance that will hide defects, nor rusted to such 
an extent as to hide defects. 



V Inspection and Eejection 



92 Inspection. The inspector representing the purchaser snail 
have free entry, at all times while work on the contract of the pur- 
chaser is being performed, to all parts of the manufacturer's works 
which concern the manufacture of the castings ordered. The manu- 
facturer shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the castings are being furnished in accordance with 



26 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

these specifications. All tests (except check analyses) and inspection 
shall be made at the place of manufacture prior to shipment, unless 
otherwise specified, and shall be so conducted as not to interfere un- 
necessarily with the operation of the works. 

93 Rejection, a Unless otherwise specified, any rejection based 
on tests made in accordance with Par. 84, shall be reported within 
five working days from the receipt of samples. 

J) Castings which show injurious defects subsequent to their ac- 
ceptance at the manufacturer's works will be rejected, and the manu- 
facturer shall be notified. 

9-1- Rehearing. Samples tested in accordance with Par. 84, 
which represent rejected castings, shall be preserved for two weeks 
from the date of the test report. In case of dissatisfaction with the 
results of the tests, the manufacturer may make claim for a rehearing 
within that time. 



SPECIFICATIONS FOR GRAY IRON CASTINGS 

THESE SPECIFICATIONS ARE IDENTICAL WITH THOSE OF THE 
AMERICAN SOCIETY FOR TESTING MATERIALS, SERIAL DESIGNATION 
A 4S-05. 

95 Process of Manufacture. Unless furnace iron is specified, all 
gray castings are understood to be made by the cupola process. 

96 Chemical Properties. The sulphur contents to be as follows : 

Light castings not over 0.08 per cent 

Medium castings not over 0.10 per cent 

Heavy Castings not over 0.12 per cent 

97 Classification. In dividing castings into light, medium and 
heavy classes, the following standards have been adopted : 

98 Castings having any section less than y 2 in. thick shall be 
known as light castings. 

99 Castings in which no section is less than 2 in. thick shall be 
known as heavy castings. 

100 Medium castings are those not included in the above classifi- 
cation. 



new installations, part i, section i, tower boilers 27 
Physical Properties and Tests 

101 Transverse Test. The minimum breaking strength of the 
"Arbitration Bar" under transverse load shall be not under: 

Light castings 2500 lbs. 

Medium eastings 2900 lbs. 

Heavy castings 3300 lbs. 

In no case shall the deflection be under 0.10 in. 

102 Tensile Test. Where specified, this shall not run less than : 

Light castings 18,000 lb. per sq. in. 

Medium castings 21,000 lb. per sq. in. 

Heavy castings 24,000 lb. per sq. in. 



JT~ 


■ 




f 2 R. 


J 


Sfd. Th react 

■ 

<- /" •— > 

->- 


r 


? 


T A 




V 




_i 




¥_ 


<-■-- -/" > 

<T 


¥i'* 


-- %J-" 

3 2 


_j*r 



Fig. 5 Standard Form of Test Specimen Eequired for Tension Tests ov 
Gray-Iron Casting Material 



103 Arbitration Bar. The quality of the iron going into castings 
under specification shall be determined by means of the "Arbitration 
Bar." This is a bar l 1 /^ in. in diameter and 15 in. long. It shall be 
prepared as stated further on and tested transversely. The tensile, 
test is not recommended, but in case it is called for, the bar as shown 
in Fig. 5, and turned up from any of the broken pieces of the trans- 
verse test shall be used. The expense of the tensile test shall fall on ; 
the purchaser. 

104 Number of Test Bars. Two sets of two bars shall be cast 
from each heat, one set from the first and the other set from the last 
iron going into the castings. Where the heat exceeds twenty tons, an 
additional set of two bars shall be cast for each twenty tons or fraction 
thereof above this amount. In case of a change of mixture during 
the heat, one set of two bars shall also be cast for every mixture other 



28 



REPORT OF BOILER CODE COMMITTEE, AM.SOCM.E. 



than the regular one. Each set of two bars is to go into a single mold. 
The bars shall not be rumbled or otherwise treated, being simply 
brushed off before testing. 

105 Method of Testing. The transverse test shall be made on all 
the bars cast, with supports 12 in. apart, load applied at the middle, 



Pipe Cope 



PATTERN 

4-" 



<\! 



-"> 



\ 






<- 



ie 



> 




1 

Fig. 6 Details of Pattern and Mold Required for Arbitration Bars in 
Testing Gray-Iron Casting Material 



and the deflection at rupture noted. One bar of every two of each set 
made must fulfill the requirements to permit acceptance of the cast- 
ings represented. 

106 Mold for Test Bar. The mold for the bars is shown in Fig. 
6. The bottom of the bar is 1/16 in. smaller in diameter than the 
top, to allow for draft and for the strain of pouring. The pattern 
shall not be rapped before withdrawing. The flask is to be rammed up 



NEW INSTALLATIONS, PART I, SECTION I. POWER BOILERS 2d 

with green molding sand, a little damper than usual, well mixed and 
put through a Xo. 8 sieve, with a mixture of one to twelve bituminous 
facing. The mold shall be rammed evenly and fairly hard, thoroughly 
dried and not cast until it is cold. The test bar shall not be removed 
from the mold until cold enough to be handled. 

107 Speed of Testing. The rate of application of the load shall 
be from 20 to 40 seconds for a deflection of 0.10 in. 

108 Samples for Analysis. Borings from the broken pieces of 
the "Arbitration Bar" shall be used for the sulphur determinations. 
One determination for each mold made shall be required. Tu case of 
dispute, the standards of the American Foun dry men's Association 
shall be used for comparison. 

109 Finish. Castings shall be true to pattern, free from cracks, 
flaws and excessive shrinkage. In other respects they shall conform 
to whatever points may be specially agreed upon. 

110 Inspection. The inspector shall have reasonable facilities 
afforded him by the manufacturer to satisfy him that the finished 
material is furnished in accordance with these specifications. All 
tests and inspections shall, as far as possible, be made at the place of 
manufacture prior to shipment. 



SPECIFICATIONS FOR MALLEABLE CASTINGS 

THESE SPECIFICATIONS ARE IDENTICAL WITH THOSE OF THE 
AMERICAN SOCIETY FOR TESTING MATERIALS, SERIAL DESIGNATION 
A 47-04. 

111 Process of Manufacture. Malleable iron castings may be 
made by the open-hearth, air furnace, or cupola process. Cupola iron, 
however, is not recommended for^heavy nor for important castings. 

112 Chemical Properties. Castings for which physical require- 
ments are specified shall not contain over 0.06 sulphur nor over 0.225 
phosphorus. 

Physical Properties and Tests 

113 Standard Test Bar. This bar shall be 1 in. sq. and 14 in. 
long, without chills and with ends left perfectly free in the mold. 
Three shall be cast in one mold, heavy risers insuring sound bars. 
Where the full heat goes into castings which are subject to specifica- 



30 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

tion, one mold shall be poured two minutes after tapping into the first 
ladle, and another mold from the last iron of the heat. Molds shall be 
suitably stamped to insure identification of the bars, the bars being 
annealed with the castings. Where only a partial heat is required for 
the work in hand, one mold should be cast from the first ladle used 
and another after the required iron has been tapped. 

a Of the three test bars from the two molds required for each 
heat, one shall be tested for tensile strength and elongation, the other 
for transverse strength and deflection. The other remaining bar is 
reserved for either the transverse or tensile test, in case of the failure 
of the two other bars to come up to requirements. The halves of the 
bars broken transversely may also be used for the tensile test. 

o Failure to reach the required limit for the tensile strength 
with elongation, as also the transverse strength with deflection, on 
the part of at least one test, shall reject the castings from that heat. 

114 Tensile Test. The tensile strength of a standard test bar 
for castings under specification shall not be less than 40,000 lb. 
per sq. in. The elongation measured in 2 in. shall not be less than 
2V2 per cent. 

115 Transverse Test. The transverse strength of a standard test 
bar, on supports 12 in. apart, pressure being applied at the center, shall 
not be less than 3000 lb., deflection being at least % in. 

116 Test Lugs. Castings of special design or of special impor- 
tance may be provided with suitable test lugs at the option of the 
inspector. At least one of these lugs shall be left on the casting for 
his inspection upon his request therefor. 

117 Annealing. Malleable castings shall neither be "over" nor 
"under" annealed. They must have received their full heat in the 
oven at least sixty hours after reaching that temperature. 

118 The "saggers" shall not be dumped until the contents shall 
at least be "black hot." 

119 Finish. Castings shall be true to pattern, free from 
blemishes, scale or shrinkage cracks. A variation of 1/16 in. per foot 
shall be permissible. Founders shall not be held responsible for 
defects due to irregular cross sections and unevenly distributed metal. 

120 Inspection. The inspector representing the purchaser shall 
have all reasonable facilities given him by the founder to satisfy him 
that the finished material is furnished in accordance with these 
specifications. All tests and inspections shall be made prior to ship- 
ment. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 81 

SPECIFICATIONS FOR BOILER RIVET IRON 

THESE REQUIREMENTS ARE AN ADAPTATION, WITH SLIGHT MODI- 
FICATIONS IN THE PHYSICAL PROPERTIES AND TESTS, OF THE SPECI- 
FICATIONS FOR ENGINE BOLT IRON OF THE AMERICAN SOCIETY FOR 
TESTING MATERIALS. 

A Requirements for Rolled Bars 

I Manufacture 

121 Process. The iron shall be made wholly from puddled iron 
or knobbled charcoal iron, and shall be free from any admixture of 
iron scrap or steel. 

122 Iron Scrap. This term applies only to foreign or bought 
scrap and does not include local mill products free from foreign or 
bought scrap. 

II Physical Properties and Tests 

123 Tension Tests, a The iron shall conform to the following 
requirements as to tensile properties: 

Tensile strength, lb. per sq. in 48,000-52,000 

Yield point, min., lb. per sq. in 0.6 tens. str. 

Elongation in 8 in., min., per cent 28 

Eeduetion of area, min., per cent 45 

b The yield point shall be determined by the drop of the beam 
of the testing machine. The speed of the cross-head of the machine 
shall not exceed 1% in. per minute. 

124 Bend Tests, a Cold-bend Tests — The test specimen shall 
bend cold through 180 deg. flat on itself without cracking on the out- 
side of the bent portion. 

b Hot-bend Tests — The test specimen, when heated to a bright 
cherry red, shall bend through 180 deg. flat on itself, without fracture 
on the outside of the bent portion. 

c Niclc-bend Tests — The test specimen, when nicked 25 per cent 
around with a tool having a 60-deg. cutting edge, to a depth of not 
less than 8 nor more than 16 per cent of the diameter of the specimen, 
and broken, shall show a wholly fibrous fracture. 

d Bend tests may be made by pressure or by blows. 



32 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E 

125 Etch Tests. 1 The cross-section of the test specimen shall be 
ground or polished, and etched for a sufficient period to develop the 
structure. This test shall show the material to be free from steel. 

126 Test Specimens. All test specimens shall be of the full sec- 
tion of material as rolled. 

127 Number of Tests, a Bars of one size shall be sorted into 
lots of 100 each. Two bars shall be selected at random from each lot 
or fraction thereof, and tested as specified in Pars. 123 and 124; but 
only one of these bars shall be tested as specified in Par. 125. 

b If any test specimen from either of the bars originally selected 
to represent a lot of material, contains surface defects not visible before 
testing but visible after testing, or if a tension test specimen breaks 
outside the middle third of the gage length, one retest from a different 
bar will be allowed. 

TIT Permissible Variation's in Gage 

128 Permissible Variations. The gage of each bar shall not vary 
more than 0.01 in. from that specified. 

IV Finish 

129 Finish. The bars shall be smoothly rolled and free from 
slivers, depressions, seams, crop ends and evidences of being burnt. 

V Marking 

130 Marking. The bars shall be stamped or marked as desig- 
nated by the purchaser. 

VI Inspection and Rejection 

131 Inspection, a The inspector representing the purchaser 
shall have free entry at all times, while work on the contract of the 
purchaser is being performed, to all parts of the manufacturer's works 
which concern the manufacture of the material ordered. The manu- 
facturer .shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the material is being furnished in accordance with 



1 A solution of two parts water, one part concentrated hydrochloric acid, and one part concen- 
trated sulphuric acid is recommended for the etch test. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 33 

these specifications. Tests and inspection at the place of manufacture 
shall be made prior to shipment. 

b The purchaser may make the tests to govern the acceptance or 
rejection of material in his own laboratory or elsewhere. .Such tests, 
however, shall be made at the expense of the purchaser. 

132 Rejection. If either of the test bars selected to represent a 
lot does not conform to the requirements specified in Pars. 12)3, 124 
and 125, the lot will be rejected. 

B Requirements for Rivets 
I Physical Properties and Tests 

133 Number of Tests. When specified, three rivets of each di- 
ameter shall be taken at random from each lot offered for inspection, 
and if they fail to stand the following tests the lot will be rejected. 

134 Bend Tests, a The rivet shank shall bend cold through 
180 deg. flat on itself, as shown in Fig. 2, without cracking on the out- 
side of the bent portion. 

b The heads must stand bending back, showing that they are 
firmly joined. 

c When nicked and broken gradually the fracture must show a 
clean, long and fibrous iron. 

II Workmanship and Finish 

135 Workmanship. The rivets shall be true to form, concentric, 
and shall be made in a workmanlike manner. 

13 6- Finish. The finished rivets shall be free from injurious de- 
fects. 

Ill Inspection and Rejection 

137 Inspection. The inspector representing the purchaser shall 
have free entry at all times, while work on the contract of the pur- 
chaser is being performed, to all parts of the manufacturer's works 
which concern the manufacture of the rivets ordered. The manu- 
facturer shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the rivets are being furnished in accordance with 
these specifications. All tests and inspection shall be made at the 



4—25018 



34 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

place of manufacture prior to shipment, unless otherwise specified, and 
shall be so conducted as not to interfere unnecessarily with the opera- 
tion of the works. 

138 Rejection. Rivets which show injurious defects subsequent 
to their acceptance at the manufacturer's works will be rejected, and 
the manufacturer shall be notified. 



SPECIFICATIONS FOR STAYBOLT IRON 

THESE SPECIFICATIONS ARE IDENTICAL WITH THOSE OF THE 
AMERICAN SOCIETY FOR TESTING MATERIALS, SERIAL DESIGNATION 
A 39-14. 

I Manufacture 

139 Process. The iron shall be rolled from a bloom or boxpile, 
made wholly from puddled iron or knobbled charcoal iron. The 
puddle mixture and the component parts of the bloom or boxpile shall 
be free from any admixture of iron scrap or steel. 

140 Definition of Terms, a Bloom — A bloom is a solid mass of 
iron that has been hammered into a convenient size for rolling. 

b Boxpile — A boxpile is a pile, the sides, top and bottom of which 
are formed by four flat bars and the interior of which consists of a 
number of small bars the full length of the pile. 

c Iron Scrap — This term applies only to foreign or purchased 
scrap and does not include local mill products free from foreign or 
purchased scrap. 

II Physcial Properties and Tests 

141 Tension Tests, a The iron shall conform to the following 
requirements as to tensile properties: 

Tensile strength, lb. per sq. in 49,000-53,000 

Yield point, min., lb. per sq. in 0.6 tens. str. 

Elongation in 8 in., min., per cent 30 

Eeduction of area, min., per cent 48 

b The yield point shall be determined by the drop of the beam 
of the testing machine. The speed of the cross-head of the machine 
shall not exceed IV2 m - P er minute. 



NEW INSTALLATIONS, PART I, SECTION I, TOWER BOILERS 35 

142 Bend Tests, a Cold-bend Tests — The test specimen shall 
bend cold through 180 deg. flat on itself in both directions without 
fracture on the outside of the bent portion. 

b Quench-bend Tests — The test specimen, when heated to a yel- 
low heat and quenched at once in water the temperature of which is 
between 80 deg. and 90 deg. fahr., shall bend through 180 deg. flat on 
itself without fracture on the outside of the bent portion. 

c Xicl m -bend Tests — The test specimen, when nicked 25 per cent 
around with a tool having a 60-deg. cutting edge, to a depth of not 
less than 8 nor more than 16 per cent of the diameter of the specimen, 
and broken, shall show a clean fiber entirely free from crystallization. 

d Bend tests may be made by pressure or by blows. 

143 Etch Tests. 1 The cross-section of the test specimen shall be 
ground or polished, and etched for a sufficient period to develop the 
structure. This test shall show the material to have been rolled from 
a bloom or a boxpile, and to be free from steel. 

144 Test Specimens. All test specimens shall be of the full sec- 
tion of material as rolled. 

145 Number of Tests, a Bars of one size shall be sorted into 
lots of 100 each. Two bars shall be selected at random from each lot 
or fraction thereof, and tested as specified in Pars. 141 and 142; but 
only one of these bars shall be tested as specified in Par. 143. 

b If any test specimen from either of the bars originally selected 
to represent a lot of material, contains surface defects not visible be- 
fore testing but visible after testing, or if a tension test specimen 
breaks outside the middle third of the gage length, one retest from a 
different bar will be allowed. 

c When retests as specified in b are not permitted, a reduction 
of 2 per cent in elongation and 3 per cent in reduction of area from 
that specified in Par. 141, shall be allowed. 



ITI Permissible Variations in Cage 

146 Permissible Variations. The bars shall be truly round 
within 0.01 in., and shall not vary more than 0.005 in. above or more 
than 0.01 in. below the specified size. 



1 A oolution of two parts water, one part concentrated hydrochloric acid, and one part'concen. 
trated sulphuric acid is recommended for the etch test. 



36 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

IV Finish 

147 Finish. The bars shall be smoothly rolled and free from 
slivers, depressions, seams, crop ends and evidences of being burnt. 

V Marking 

148 Marking. The bars shall be stamped or marked as desig- 
nated by the purchaser. 

VI Inspection and Eejection 

149 Inspection, a The inspector representing the purchaser 
shall have free entry, at all times while work on the contract of the 
purchaser is being performed, to all parts of the manufacturer's works 
which concern the manufacture of the material ordered. The manu- 
facturer shall afford the inspector, free of cost, all reasonable facilities 
to satisfy him that the material is being furnished in accordance with 
these specifications. Tests and inspection at the place of manufacture 
shall be made prior to shipment. 

b The purchaser may make the tests to govern the acceptance or 
rejection of material in his own laboratory or elsewhere. Such tests, 
however, shall be made at the expense of the purchaser. 

150 Eejection. a If either of the test bars selected to represent 
a lot does not conform to the requirements specified in Pars. 141, 142 
and 143, the lot will be rejected. 

b Bars which will not take a clean, sharp thread with dies in fair 
condition, or which develop defects in forging or machining, will be 
rejected, and the manufacturer shall be notified. 



NEW INSTALLATIONS, PART I, SECTION I, TOWER BOILERS 37 

SPECIFICATIONS FOR REFINED WROUGHT-IRON 

BARS 

THESE SPECIFICATIONS ARE SIMILAR TO THOSE OF THE AMERICAN 
SOCIETY FOR TESTING MATERIALS, SERIAL DESIGNATION A 41-13. 

I Manufacture 

151 Process. Refined wrought-iron bars shall be made wholly 
from puddled iron, and may consist either of new muck-bar iron or a 
mixture of muck-bar iron and scrap, but shall be free from any ad- 
mixture of steel. 

II Physical Properties and Tests 

152 Tension Tests, a The iron shall conform to the following 
minimum requirements as to tensile properties. 

Tensile strength, lb. per sq. in 48,000 

(See Pars. 153 and 154.) 

Yield point, lb. per sq. in 25,000 

Elongation in 8 in., per cent 22 

(See Par. 155.) 

b The yield point shall be determined by the drop of the beam 
of the testing machine. The speed of the cross-head of the machine 
shall not exceed V/ 2 in. per minute. 

153 Permissible Variations. Twenty per cent of the test speci- 
mens representing one size may show tensile strengths 1000 lb. per 
sq. in. under, or 5000 lb. per sq. in. over that specified in Par. 152 ; 
but no specimen shall show a tensile strength under 45,000 lb. per 
sq. in. 

154 Modifications in Tensile Strength. For flat bars which have 
to be reduced in width, a deduction of 1000 lb. per sq. in. from the 
tensile strength specified in Pars. 152 and 153, shall be made. 

155 Permissible Variations in Elongation. Twenty per cent of 
the test specimens representing one size may show the following per- 
centages of elongation in 8 in. : 

BOUND BAES 

y<2, in. or over, tested as rolled 20 per cent 

Under y 2 in., tested as rolled 16 per cent 

Reduced by machining 18 per cent 



38 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

FLAT BARS 

% in. or over, tested as rolled 18 per cent 

Under % in., tested as rolled 16 per cent 

Reduced by machining 16 per cent 

156 Bend Tests, a Cold-bend Tests — Cold bend tests will be 
made only on bars having a nominal area of 4 sq. in. or under, in 
which case the test specimen shall bend cold through 180 deg. without 
fracture on the outside of the bent portion, around a pin the diameter 
of which is equal to twice the diameter or thickness of the specimen. 

o Hot-bend Tests — The test specimen, when heated to a tempera- 
ture between 1700 deg. and 1800 deg. fahr., shall bend through 180 
deg. without fracture on the outside of the bent portion, as follows: 
for round bars under 2 sq. in. in section, flat on itself; for round bars 
2 sq. in. or over in section and for all flat bars, around a pin the 
diameter of which is equal to the diameter or thickness of the specimen. 

c Nick-bend Tests — The test specimen, when nicked 25 per cent 
around for round bars, and along one side for flat bars, with a tool 
having a 60-deg. cutting edge, to a depth of not less than 8 nor more 
than 16 per cent of the diameter or thickness of the specimen, and 
broken, shall not show more than ,10 per cent of the fracture surface 
to be crystalline. 

d Bend tests may be made by pressure or by blows. 

157 Etch Tests. 1 The cross-section of the test specimen shall be 
ground or polished, and etched for a sufficient period to develop the 
structure. This test shall show the material to be free from steel. 

158 Test Specimens, a Tension and bend test specimens shall 
be of the full section of material as rolled, if possible; otherwise the 
specimens shall be machined from the material as rolled. The axis 
of the specimen shall be located at any point one-half the distance 
from the center to the surface of round bars, or from the center to 
the edge of flat bars, and shall be parallel to the axis of the bar. 

b Etch test specimens shall be of the full section of material as 
rolled. 

159 Number of Tests, a All bars of one size shall be piled 
separately. One bar from each 100 or fraction thereof will be selected 
at random and tested as specified. 

b If any test specimen from the bar originally selected to repre- 
sent a lot of material contains surface defects not visible before test- 



J A solution of two parts water, one part concentrated hydrochloric acid, and one part con- 
centrated sulphuric acid is recommended for the etch test. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 



39. 



ing but visible after testing, or if a tension test specimen breaks outside 
the middle third of the gage length, one retest from a different bar 
will be allowed. 

Ill Permissible Variations in Gage 

160 Permissible Variations, a Round bars shall conform to the 
standard limit gages adopted by the Master Car Builders' Association 
given in Table 2. 



TABLE 2 PERMISSIBLE VARIATIONS IN GAGE FOR ROUND WROUGHT-IRON BARS 



Nominal 

Diameter 

Inches 

M 

A 

%■■■■■ 

.2 

ft:::: 

% 

Vs 

1 

1H 

IK 



Maximum 

Diameter, 

Inches 



Minimum 

Diameter, 

Inches 



Total 

Variation, 

Inches 



0.2550 
0.3180 
0.3810 
0.4440 
5070 
0.5700 
0.6330 
0.7585 
0.8840 
1 . 0095 
1.1350 
1.2605 



0.2450 

0.3070 

0.3690 

.4310 

,4930 

5550 

6170 

7415 

.8600 

0.9905 

1.1150 

1.2395 



0.010 
0.011 
0.012 
0.013 
0.014 
. 015 
0.016 
0.017 
0.018 
0.019 
0.020 
0.021 



b The widths or thicknesses of flat bars shall not vary more than 
2 per cent from that specified. 

IV Finish 

161 Finish. The bars shall be smoothly rolled and free from 
slivers, depressions, seams, crop ends and evidences of being burnt. 



V Inspection and Rejection 

162 Inspection, a The inspector representing the purchaser 
shall have free entrjr, at all times while work on the contract of the 
purchaser is being performed, to all parts of the manufacturer's 
works which concern the manufacture of the material ordered. The 
manufacturer shall afford the inspector, free of cost, all reasonable 
facilities to satisfy him that the material is being furnished in ac- 
cordance with these specifications. Tests and inspection at the place 
of manufacture shall be made prior to shipment. 

b The purchaser may make the tests to govern the acceptance 
or rejection of material in his own laboratory or elsewhere. Such 
tests, however, shall be made at the expense of the purchaser. 



46 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

163 Rejection. All bars of one size will be rejected if the test 
specimens representing that size do not conform to the requirements 
specified. 



SPECIFICATIONS FOR LAPWELDED AND SEAMLESS 
BOILER TUBES 

Approved by the Boiler Tube Manufacturers of America 
September 25, 1914 

I Manufacture 

164 Process, a Lapwelded tubes shall be made of open-hearth 
steel or knobbled hammered charcoal iron. 

o Seamless tubes shall be made of open-hearth steel. 

II 'Chemical Properties and Tests 

165 CJtemical Composition, a The steel shall conform to the 
following requirements as to chemical composition: 

Carbon 0.08-0.18 per cent 

Manganese 0.30-0.50 per cent 

Phosphorus not over 0.04 per cent 

Sulphur not over 0.045 per cent 

b Chemical analyses will not be required for charcoal iron tubes. 

166 Chech Analyses, a Analyses of two tubes in each lot of 
250 (or on total order if less than 250) may be made by the purchaser 
which shall conform to the requirements specified in Par. 165. Drill- 
ings for analyses shall be taken from several points around each tube. 

b If the analysis of only one tube does not conform to the re- 
quirements specified, analyses of two additional tubes from the same 
lot shall be made, each of which shall conform to the requirements 
specified. 

III Physical Properties and Tests 

167 Flange Test, a A test specimen not less than 4 in. in length 
shall have a flange turned over at right angles to«the body of the tube 



NEW INSTALLATIONS, PART I, SECTION I, TOWER BOILERS 



41 



This flange as measured from the 



tool and die block as 



without showing cracks or flaws 
outside of the tube shall be % in. wide. 

b In making the flange test, the flarin^ 
shown in Fig. 7, may be used. 

168 Flattening Tests. A test specimen 3 in. in length shall 
stand hammering flat until the inside walls are brought parallel and 
separated by a distance equal to three (3) times the wall thickness, 
without showing cracks or flaws. In the case lapwelded tubes, the 
test shall be made with the weld at the point of maximum bend. 



< CO 



FLARING TOOL 
A = OS. Diam. of Tube less § " 

B- - I" 

c " P'^h" 



Posit ion after using Flaring Tool 
\ing 
Flatter 




k--A -^"^L /'tiers 
DIE BLOCK 
A = O.S. Diam. of Tube + ^ 



Fig. 7 Details of Flaring Tool and Die Block Bequired for Making 
Flange Tests of Boiler Tubes 



169 Hydrostatic Tests. Tubes under 5 in. in diameter shall stand 
an internal hydrostatic pressure of 1000 lb. per sq. in. and tubes 5 in. 
in diameter or over, an internal hydrostatic pressure of 800 lb. per sq. 
in. Lapwelded tubes shall be struck near both ends, while under pres- 
sure, with a two-pound hand hammer or the equivalent. 

170 Test Specimens, a All test specimens shall be taken from 
tubes before being cut to finished lengths and shall be smooth on the 
ends and free from burrs, b All tests shall be made cold. 

171 Number of Tests. One flange and one flattening test shall 
be made from each of two tubes in each lot of 250 or less. Each tube 
shall be subjected to the hydrostatic test. 

172 Retests. If the result of the physical tests of only one tube 
from any lot do not conform to the requirements specified in Pars. 167 
and 168, retests of two additional tubes from the same lot shall be 
made, each of which shall conform to the requirements specified. 



42 REPORT OF BOTLER CODE COMMITTEE, AM.SOC.M.E. 

ETCH TESTS FOR CHARCOAL IRON" 

1,73 Etch Tests. 1 A cross section of tube may be turned or 
ground to a perfectly true surface polished free from dirt or cracks, 
and etched until the soft parts are sufficiently dissolved for the iron 
tube to show a decided ridged surface with the weld very distinct, 
while a steel tube would show a homogeneous surface. 

IV Workmanship and Finish 

174 Workmanship. The finished tubes shall be circular within 
0.02 in. and the mean outside diameter shall not vary more than 0.015 
in. from the size ordered. All tubes shall be carefully gaged with a 
B.W.G. gage and shall not be less than the gage specified, except 
the tubes on which the standard slot gage, specified, will go on 
tightly at the thinnest point, will be accepted. The length shall not 
be less, but may be 0.125 in. more than that ordered. 

175 Finish. The finished tubes shall be free from injurious de- 
fects and shall have a workmanlike finish and shall be practically free 
from kinks, bends and buckles. 

V Marking 

17G Marling. The name or brand of the manufacturer, the ma- 
terial from which it is made, whether steel or charcoal iron, and 
"Tested at 1000 lb." for tubes under 5 in. in diameter, or "Tested at 
800 lb." for tubes 5 in. in diameter or over, shall be legibly stenciled 
on each tube. 

VI Inspection and Eejection 

177 Inspection. All tests and inspection shall be made at the 
place of manufacture. The manufacturer of boiler tubes shall furnish 
the purchaser of each lot of tubes a statement of the kind of material 
of which the tubes are made, and that the tubes have been tested and 
have met all the requirements of these rules. This statement shall be 
furnished to the manufacturer using the tubes. 

178 Eejection. Tubes when inserted in the boiler shall stand 
expanding and beading without showing cracks or flaws, or opening 
at the weld. Tubes which fail in this manner will be rejected and the 
manufacturer shall be notified. 



1 A. solution of two parts of water, one part concentrated hydrochloric acid, and one part 
concentrated sulphuric acid is recommended for the etch test. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 40 



Construction and Maximum Allowable "Working Pressures 
for Power Boilers 

179 Maximum Allowable Working Pressure. The maximum al- 
lowable working pressure is that at which a boiler may be operated as 
determined by employing the factors of safety, stresses, and dimensions 
designated in these Rules. 

Xo boiler shall be operated at a higher pressure than the maxi- 
mum allowable working pressure except when the safety valve or 
valves are blowing, at which time the maximum allowable working- 
pressure shall not be exceeded by more than six per cent. 

Wherever the term maximum allowable working pressure is used 
herein, it refers to gage pressure, or the pressure above the atmosphere, 
in pounds per square inch. 

180 The maximum allowable working pressure on the shell of a 
boiler or drum shall be determined by the strength of the weakest 
course, computed from the thickness of the plate, the tensile strength 
stamped thereon, as provided for in Par. 36, the efficiency of the 
longitudinal joint, or of the ligament between the tube holes in shell 
or drum, (whichever is the least), the inside diameter of the course, 
and the factor of the safety. 

TSXtXE 

— -r — == maximum allowable working pressure, lb. per sq. in. 

exfs 

where 

TS = ultimate tensile strength stamped on shell plates, as 
provided for in Par. 3.6, lb. per sq. in. 

i = minimum thickness of shell plates in weakest course, in. 

E = efficiency of longitudinal joint or of ligaments between 
tube holes (whichever is the least) 

R = inside radius of the weakest course of the shell or 
drum, in. 

FS = factor of safety, or the ratio of the ultimate strength of 
the material to the allowable stress. For new con- 
structions covered in Part I, FS in the above for- 
mula = 5. 



m report of boiler code committee, am.soc.m.e. 

Boiler Joints 

181 Efficiency of a Joint. The efficiency of a joint is the ratio 
which the strength of the joint bears to the strength of the solid 
plate. In the case of a riveted joint this is determined by calculating 
the breaking strength of a unit section of the joint, considering each 
possible mode of failure separately, and dividing the lowest result by 
the breaking strength of the solid plate of a length equal to that of the 
section considered. (See Appendix, Par. 410 to 416, for detailed 
methods and examples.) 

183 The distance between the center lines of any two adjacent 
rows of rivets, or the "back pitch" measured at right angles to the 
direction of the joint, shall be at least twice the diameter of the rivets 
and shall also meet the following requirements : 

a Where each rivet in the inner row comes midway between 
two rivets in the outer row, the sum of the two diagonal 
sections of the plate between the inner rivet and the two 
outer rivets shall be at least 20 per cent greater than the 
section of the plate between the two rivets in the outer 
row. 
o Where two rivets in the inner row come between two rivets 
in the outer row, the sum of the two diagonal sections of 
the plate between the two inner rivets and the two rivets 
in the outer row shall be at least 20 per cent greater than 
the difference in the section of the plate between the two 
rivets in the outer row and the two rivets in the inner row. 

183 On longitudinal joints, the distance from the centers of 
rivet holes to the edges of the plates, except rivet holes in the ends of 
butt straps, shall be not less than one and one-half times the diameter 
of the rivet holes. 

184 a Circumferential Joints. The strength of circumferential 
joints of boilers, the heads of which are not stayed by tubes or through 
braces shall be at least 50 per cent that of the longitudinal joints of the 
same structure. 

o When 50 per cent or more of the load which would act on an 
unstayed solid head of the same diameter as the shell, is relieved by the 
effect of tubes or through stays, in consequence of the reduction of the 
area acted on by the pressure and the holding power of the tubes and 
stays, the strength of the circumferential joints in the shell shall be 
at least 35 per cent that of the longitudinal joints. 

185 When she'll plates exceed 9/16 in. in thickness in horizontal 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 45 

return tubular boilers, the portion of the plates forming the laps of the 
circumferential joints, where exposed to the fire or products of com- 
bustion, shall be planed or milled clown as shown in Fig. 8, to y 2 in. 
in thickness, provided the requirement in Par. 184 is complied with. 

18.G Welded Joints. The ultimate tensile strength of a longi- 
tudinal joint which has been properly welded by the forging process, 
shall be taken as ,2i8,500 lb. per sq. in., with steel plates having a range 
in tensile strength of 47,000 to 55,000 lb. per sq. in. 

187 Longitudinal Joints. The longitudinal joints of a shell or 
drum which exceeds 36 in. in diameter, shall be of butt and double- 
strap construction. 

188 The longitudinal joints of a shell or drum which does not 




Fig. 



Circumferential Joint for Thick Plates of Horizontal Eeturn 
Tubular Boilers 



exceed 36 in. in diameter, may be of lap-riveted construction; but the 
maximum allowable working pressure shall not exceed 100 lb. per 
sq. in. 

189 The longitudinal joints of horizontal return tubular boilers 
shall be located above the fire-line of the setting. 

190 A horizontal return tubular boiler on which a longitudinal 
lap joint is permitted shall not have a course over 12 ft. in length. 
With butt and double-strap construction, longitudinal joints of any 
length may be used provided the plates are tested transversely to 
the direction of rolling, which tests shall show the standards pre- 
scribed under the Specifications of Boiler Plate Steel. 

191 Butt straps and the ends of shell plates forming the longi- 
tudinal joints shall be rolled or formed by pressure, not blows, to the 
proper curvature. 



16 



report of boiler code committee, am.soc.m.e. 
Ligaments 



192 Efficiency of Ligament. When a shell or drum is drilled for 

tubes in a line parallel to the axis of the shell or drum, the efficiency 

of the ligament between the tube holes shall be determined as follows : 

a When" the pitch of the tube holes on every row is equal (Fig. 

9), the formula is : 

p — d 



where 



P 



= efficiency of ligament 

p = pitch of tube holes, in. 
d = diameter of tube holes, in. 







■slf-^sH 



^e^K^B- 



Longitudinal Line ^- 

Fig. 9 Example of Tube Spacing with Pitch of 
Holes Equal in Every Eow 



Example: Pitch of tube holes in the drum as shown in Fig. 9 
= 5*4 in- Diameter of tubes ■= 314 in. Diameter of tube holes = 
3 9/32 in. 



p—d 



.25— 3.281 
_ 5725 



0.375, efficiency of ligament 






e-gH&^-o-e-o-e- 



h<—.-f£ ^ 

.Longitudinal Line 



Fig. 10 Example of Tube Spacing with Pitch 
of Holes Unequal in Every Second Eow 



When the pitch of tube holes on any one row is unequal (as 
in Figs. 10 or 11), the formula is: 

. = efficiency of ligament 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 



41 



where 

p = unit length of ligament, in. 

n = number of tube holes in length, p. 

d = diameter of tube holes, in. 

Example: Spacing shown in Fig. 10. Diameter of tube holes = 
3 9/3-2 in. 

p—ncl 42— 2X3.281 



P 



12 



0.453, efficiency of ligament 



Example: Spacing shown in Fig. 11. Diameter of tube holes 
= 3 9/32 in. 

p—nd 29.25— 5X3.281 

■ = ~ q o f, = 0.43-9, efficiency of ligament 



«-5| tf ->T<-6i--><-54 f '->^:-5| -><-6 1 



6¥'-><r5k'-^5k'^<r6¥->r«S¥~>\*-**- 




^^)-<iH^B-e-q>-<B^^ 



<$H$-0- 



Sf^rSW 



Longitudinal Line 



Fig. 11 Example of Tube Spacing with Pitch of Holes 
Varying in Every Second and Third Eow 



193 When a shell or drum is drilled for tube holes in a line 
diagonal with the axis of the shell or drum as shown in Fig. 12, the 
efficiency of the ligament between the tube holes shall be determined 
by the following methods and the lowest value used. 



0.95 (jv- d) 



efficiency of ligament 



b 
where 



p — d 



— efficiency of ligament 



p t = diagonal pitch of tube holes, in. 
d = diameter of tube holes, in. 

p = longitudinal pitch of tube holes or distance between 
centers of tubes in a longitudinal row, in. 



The constant 0.95 in formula a applies provided ^~ is 1.5 or over. 



48 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



Example : Diagonal pitch of tube holes in drum as shown in Fig. 
12 = 6.42 in. 

Diameter of tube holes = 4 1/32 in. 
Longitudinal pitch of tube holes = 11% in. 

0.95(6.42—4.031) 



b 



6.42 

11.5—4.031 
11.5 



0.353, efficiency of ligament 
= 0.649, efficiency of ligament 



The value determined by formula a is the least and is the one that 
shall be used in this case. 




^##P 






Longitudinal Line 



Fig. 12 Example op Tube Spacing with Tube Holes on Diagonal Lines 



194 Domes. The longitudinal joint of a dome 24 in. or over in 
diameter shall be of butt and double-strap construction, and its flange 
shall be double riveted to the boiler shell when the maximum allowable 
working pressure exceeds 100 lb. per sq. in. 

The longitudinal joint of a dome less than 24 in. in diameter may 
be of the lap type, and its flange may be single riveted to the boiler 
shell provided the maximum allowable working pressure on such a 
dome is computed with a factor of safety of not less than 8. 

The dome may be located on the barrel or over the fire-box on 
traction, portable or stationary boilers of the locomotive type up to 
and including 48 in. barrel diameter. For larger barrel diameters, the 
dome shall be placed on the barrel. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 49 

Dished Heads 

195 Convex Heads. The thickness required in an unstayed 
dished head with the pressure on the concave side, when it is a seg- 
ment of a sphere, shall be calculated by the following formula : 

, 5.5XPXL 

it= 2XT8 + /s 

where 

t = thickness of plate, in. 

P = maximum allowable working pressure, lb. per sq. in. 
TS = tensile strength, lb. per sq. in. 
L = radius to which the head is dished, in. 
Where the radius is less than 80 per cent of the diameter of the 
shell or drum to which the head is attached the thickness shall be at 
least that found by the formula by making L equal to 80 per cent of 
the diameter of the shell or drum. 

Concave Heads. Dished heads with the pressure on the convex 
side shall have a maximum allowable working pressure equal to 60 
per cent of that for heads of the same dimensions with the pressure 
on the concave side. 

When a dished head has a manhole opening, the thickness as 
found by these Eules shall be increased by not less than % in. 

196 Y\ r hen dished heads are of a less thickness than called for 
by Par. 195, they shall be stayed as flat surfaces, no allowance being 
made in such staying for the holding power due to the spherical form. 

197 The corner radius of an unstayed dished head measured on 
the concave side of the head shall not be less than iy 2 in. or more 
than 4 in. and within these limits shall be not less than 3 per cent of 
L in Par. 195. 

198 A manhole opening in a dished head shall be flanged to a 
depth of not less than three times the thickness of the head measured 
from the outside. 

Braced and Stayed Surfaces 

199 The maximum allowable working pressure for various 
thicknesses of braced and stayed flat plates and those which by these 
Eules require staying as flat surfaces with braces or staybolts of uni- 



50 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

form diameter symmetrically spaced, shall be calculated by the 
formula : 

where 

P = maximum allowable working pressure, lb. per sq. in. 

t = thickness of plate in sixteenths of an inch 

P — maximum pitch measured between straight lines passing 
through the centers of the staybolts in the different 
rows, which lines may be horizontal, vertical or in- 
clined, in. 

C = 112 for stays screwed through plates not over 7/16 in. 
thick with ends riveted over 

C — : 120 for stays screwed through plates over 7/16 in. thick 
with ends riveted over 

0—135 for stays screwed through plates and fitted with 
single nuts outside of plate 

C = 175 for stays fitted with inside and outside nuts and 
outside washers where the diameter of washers is not 
less than OAp and thickness not less than t. 
If flat plates not less than % in. thick are strengthened with doubling 
plates securely riveted thereto and having a thickness of not less 
than 2/3 t, nor more than t, then the value of t in the formula shall 
be % of the combined thickness of the plates and the values of C 
given above may also be increased 15 per cent. 

200 Staybolts. The ends of screwed staybolts shall be riveted 
over or upset by equivalent process. The outside ends of such staybolts 
shall be drilled with a hole at least 3/16 in. diameter to a depth ex- 
tending Y2 in. beyond the inside of the plates, except on boilers having 
a grate area not exceeding 15 sq. ft., where the drilling of the staybolts 
is optional. 

,201 When channel irons or other members are securely riveted 
to the boiler heads for attaching through stays the transverse stress 
on such members shall not exceed 12,500 lb. per sq. in. In computing 
the stress, the section modulus of the member shall be used without 
addition for the strength of the plate. The spacing of the rivets over 
the supported surface shall be in conformity with that specified for 
staybolts. 



NEW INSTALLATIONS, TART I, SECTION I, POTTER BOILERS 



51 



#02 The ends of sta} T s fitted with nuts shall not be exposed to 
the direct radiant heat of the fire. 

203 The maximum spacing between centers of rivets attaching 
the crowfeet of braces to the braced surface, shall be determined by 
the formula in Par. 199, using 135 for value of C. 

The m;)" ; mum spacing between the inner surface of the shell and 
lines parallel to the surface of the shell passing through the centers 
of the rivets attaching the crowfeet of braces to the head, shall be 
determined by the formula in Par. 199, using 160 for the value of C. 



TABLE 3 MAXIMUM ALLOWABLE PITCH, IN INCHES, OF SCREWED STAYBOLTS, 
ENDS RIVETED OVER 





Pressure, 
Lb. per Sq. In. 






Thickness of Plat* 


i, In. 








A 


H 


7 
16 


A 


9 
16 


S A 


n 

16 








Maximum Pitch of Staybolts, I 


a. 






100 
110 
120 
125 
130 
140 
150 
160 
170 
180 
190 
200 
225 
250 
300 


5J€ 
5 

m 

4K 

4M 

4^ 
4 


6 

5 

4M 
4 


7% 

7 

6M 

6^ 

6V 2 

6M 

6 

5% 
5 5 A 
5V 2 

5M 

m 

4J€ 












8 

7% 

7 5 A 

7% 

7H 

W% 

QVs 

GVs 
5V 8 
5A 
5 


































8Vs 

8 

7H 

iy% 

7% 

7V S 

7 

QV 2 

6M 

$A 




















8A 
7% 
7H 
7H 

VA 

6M 


















SA 
8 










7*A 

7 















204 The formula in Par. 199 was used in computing Table 3. 
Where values for screwed stays with ends riveted over are required for 
conditions not given in Table 3, they may be computed from the 
formula and used, provided the pitch does not exceed 8% in. 

205 The distance from the edge of a staybolt hole to a straight 
line tangent to the edges of the rivet holes may be substituted for p 
for staybolts adjacent to the riveted edges bounding a stayed surface. 
When the edge of a stayed plate is flanged, p shall be measured from 
the inner surface of the flange, at about the line of rivets to the edge 
of the staybolts or to the projected edge of the staybolts. 



52 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



206 The distance between the edges of the staybolt holes may be 
substituted for p for staybolts adjacent to a furnace door or other 
boiler fitting, tube hole, hand hole or other opening. 

'•207 In water leg boilers, the staybolts may be spaced at greater 
distances between the rows than indicated in Table 3, provided the 
portions of the sheet which come between the rows of staybolts have 
the proper transverse strength to give a factor of safety of at least 5 
at the maximum allowable working pressure. 

208 The diameter of a screw stay shall be taken at the bottom of 
the thread, provided this is the least diameter. 




Fig. 13 Method of Determining Net Area of Segment of a Head 



209 The least cross-sectional area of a stay shall be taken in calcu- 
lating the allowable stress, except that when the stays are welded and 
have a larger cross-sectional area at the weld than at some other point, 
in which case the strength at the weld shall be computed as well as in 
the solid part and the lower value used. 

210 Holes for screw stays shall be drilled full size or punched 
not to exceed % in- less than full diameter of the hole for plates over 
5/16 in. in thickness, and % in. less than the full diameter of the 
hole for plates not exceeding 5/16 in. in thickness, and then drilled 
or reamed to the full diameter. The holes shall be tapped fair and 
true, with a full thread. 

211 The ends of steel stays upset for threading, shall be thor- 
oughly annealed. 

212 An internal cylindrical furnace which requires staying shall 
be stayed as a flat surface as indicated in Table 3. 



NEW INSTALLATIONS, PART I, SECTION I, POTHER BOILERS 



53 



213 Staying Segments of Heads. A segment of a head shall 
be stayed by head to head, through, diagonal, crowfoot or gusset stays, 
except that a horizontal return tubular boiler may be stayed as pro- 
vided in Pars. 225 to 229. 

,214 Areas of Segments of Heads to oe Stayed. The area of a 
segment of a head to be stayed shall be the area enclosed by lines drawn 
3 in. from the shell and 2 in. from the tubes, as shown in Figs. 13 
and 11. 

215 In water tube boilers, the tubes of which are connected to 
drum heads, the area to be stayed shall be taken as the total area of 
the head less a 5 in. annular ring, measured from the inner circum- 
ference of the drum shell. 




Fig. 14 Method of Determining Net Area of Irregular 
Segment of a Head 



When such drum heads are 30 in. or less in diameter and the 
tube plate is stiffened by flanged ribs or gussets, no stays need be used 
if a hydrostatic test to destruction of a boiler or unit section built in 
accordance with the construction, shows that the factor of safety is at 
least 5. 

216 In a Are tube boiler, stays shall be used in the tube sheets if 
the distances between the edges of the tube holes exceed the maximum 
pitch of staybolts given in Table 3. That part of the tube sheet which 
comes between the tubes and the shell, need not be stayed when the 
distance from the inside of the shell to the outer surface of the tubes 
does not exceed that given by the formula in Par. 199, using 160 for 
the value of C. 



54 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



217 The net area to be stayed in a segment of a head may be de- 
termined by the following formula : 



4 (H—5) 






-0.608 = area to be stayed, sq. in. 



where 



II — distance from tnbes to shell, in. 

R = radius of boiler head, in. 
218 When the portion of the head below the tubes in a horizon- 
tal return tubular boiler is provided with a manhole opening, the 
flange of which is formed from the solid plate and turned inward 
to a depth of not less than three times the thickness of the head, meas- 
ured from the outside, the area to be stayed as indicated in Fig. 14, 
may be reduced by 100 sq. in. The surface around the manhole shall 
be supported by through stays with nuts inside and outside at the front 
head. 



TABLE 4 MAXIMUM ALLOWABLE STRESSES FOR STAYS AND 
STAYBOLTS 





Stresses, Lb. per Sq. In. 


Description of Stays 


For Lengths between 
Supports not Exceed- 
ing 120 Diameters 


For Lengths between 

Supports Exceeding 

120 Diameters 


a Unwelded stays less than twenty diameters long 

screwed through plates with ends riveted over . . 

b Unwelded stays and unwelded portions of welded 


7500 

9500 
6000 


8500 




6000 







219 When stay rods are screwed through the sheets and riveted 
over, they shall be supported at intervals not exceeding 6 ft. In boilers 
without manholes, stay rods over 6 ft. in length may be screwed 
through the sheets and fitted with nuts and washers on the outside. 

220 The maximum allowable stress per square inch net cross 
sectional area of stays and staybolts shall be as given in Table 4. 

The length of the stay between supports shall be measured from 
the inner faces of the stayed plates. The stresses are based on tension 
only. For computing stresses in diagonal stays, see Pars. 2,21 and 222. 

221 Stresses in Diagonal and Gusset Stays. Multiply the area 
of a direct stay required to support the surface by the slant or diagonal 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 55 

length of the stay; divide this product by the length of a line drawn 
at right angles to surface supported to center of palm of diagonal stay. 
The quotient will be the required area of the diagonal stay. 



A = 



aXL 
I 



where 



A = sectional area of diagonal stay, sq. in. 
a = sectional area of direct stay, sq. in. 
L = length of diagonal stay, as indicated in Fig. 15, in. 
I — length of line drawn at right angles to boiler head or 

surface supported to center of palm of diagonal stay, 

as indicated in Fig. 15, in. 




Fig. 15 Measurements for Determining Stresses in 
Diagonal Stats 



Given diameter of direct stay = 1 in., a = 0.7854, L 
I = 48 in. ; substituting and solving : 



GO in., 



A = 



0.7854X60 

48 



0.981 sectional area, sq. in. 



Diameter ■= 1.11 in. == 1% in. 

222 For staying segments of tube sheets such as in horizontal 
return tubular boilers, where L is not more than 1.15 times I for any 
brace, the stays may be calculated as direct stays, allowing 90 per cent 
of the stress given in Table 4. 

223 Diameter of Pins and Area of Rivets in Brace. The sec- 
tional area of pins to resist double shear and bending when secured in 
crowfoot, sling, and similar stays shall be at least equal to three- 



56 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



fourths of the required cross-sectional area of the brace. The com- 
bined cross section of the eye at the sides of the pin shall be at least 
25 per cent greater than the required cross-sectional area of the brace. 
The cross-sectional area of the rivets attaching a brace to the 
shell or head shall be not less than one and one quarter times the re- 
quired sectional area of the brace. Each branch of a crowfoot shall 
be designed to carry two-thirds of the total load on the brace. The 
net sectional areas through the sides of the crowfeet, tee irons or 
similar fastenings at the rivet holes shall be at least equal to the re- 
quired rivet section. All rivet holes shall be drilled and burrs removed, 
and the pins shall be made a neat fit. 

TABLE 5 SIZES OF ANGLES REQUIRED FOR STAYING SEGMENTS OF HEADS 
With the short legs of the angles attached to the head of the boiler 





30" Boiler 


34" Boiler 


36" Boiler 




Height 
of 


Angle 


Angle 


Angle 


Angle 


Angle 


Angle 


Angle 


Angle 


Angle 


Dimen- 


Segment, 


3"x2V 2 " 


3J^"x3" 


4"x3" 


3K"x3" 


4"x3" 


5"x3" 


4"x3" 


5"x3" 


6"x3^" 


sion 
A in 


Dimension B 








































in Fig. 16 


Thick- 


Thick- 


Thick- 


Thick- 


Thick- 


Thick- 


Thick- 


Thick- 


Thick- 


Fig. 16 




ness, 


ness, 


ness, 


ness, 


ness, 


ness, 


ness, 


ness, 


ness, 






inches 


inches 


inches 


inches 


inches 


inches 


inches 


inches 


inches 




10 


H 


5 

16 


s 

16 


— 


— 


— 


— 


— 


— 


6K 


11 


A 


H 


_5_ 
« 16 


16 


16 


A 


— 


— 


— 


7 


12 


_9- 
16 


A 


H 


y 2 


A 


A 


A 


A 


— 


7H 


13 


— 


A 


16 


H 


y 2 


A 


& 


H 


— 


8 


14 


— 


— 


H 


— ■ 


% 


N 


% 


& 


Vs 


8H 


15 












K 


M 


H 


% 


9 


16 
















H 


& 


9V2 



224 Gusset stays when constructed of triangular right-angled web 
plates secured to single or double- angle bars along the two sides 
at right angles shall have a cross-sectional area (in a plane at right 
angles to the longest side and passing through the intersection of the 
two shorter sides) not less than 10 per cent greater than would be 
required for a diagonal stay to support the same surface, figured by the 
formula in Par. 2;21, assuming the diagonal stay is at the same angle 
as the longest side of the gusset plate. 

2.25 Staying of Upper Segments of Tube Heads by Steel Angles. 
When the shell of a boiler does not exceed 36 in. in diameter and is 
designed for a maximum allowable working pressure not exceeding 100 
lb. per sq. in., the segment of heads above the tubes may be stayed by 
steel angles as specified in Table 5 and Fig. 16, except that angles of 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 



57 



equal thickness and greater depth of outstanding leg, or of greater 
thickness and the same depth of outstanding leg, may be substituted for 
those specified. The legs attached to the heads may vary in depth 
y 2 in. above or below the dimensions specified in Table 5. 

226 When this form of bracing is to be placed on a boiler, the 
diameter of which is intermediate to or below the diameters given in 
Table 5, the tabular values for the next higher diameter shall govern. 
Eivets of the same diameter as used in the longitudinal seams of the 
boiler shall be used to attach the angles to the head and to connect 
the outstanding legs. 



Not over 3". 

o!o olo OX 

ft ± T 



Not over 3" 



-Not] over 4"- 



OOOIOOO 

ooolooo 
oooiooo 
oo'oo 

CD 



£ 



I Not less x 
'/than 2" -^ 



Fig. 16 Staying of Head with Steel Angles in Tubular Boiler 



,227 The rivets attaching angles to heads shall be spaced not 
over 4 in. apart. The centers of the end rivets shall be not over 3 in. 
from the ends of the angle. The rivets through the outstanding legs 
shall be spaced not over 8 in. apart ; the centers of the end rivets shall 
be not more than 4 in. from the ends of the angles. The ends of the 
angles shall be considered those of the outstanding legs and the lengths 
shall be such that their ends overlap a circle 3 in. inside the inner 
surface of the shell as shown in Fig. 16. 

228 The distance from the center of the angles to the shell of 
the boiler, marked A in Fig. 16, shall not exceed the values given in 
Table 5, but in no case shall the leg attached to the head on the lower 
angle come closer than 2 in. to the top of the tubes. 



58 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

2,29 When segments are beyond the range specified in Table 5, 
the heads shall be braced or stayed in accordance with the requirements 
in these Eules. 

230 Crown Bars and Girder Stays. 'Crown bars and girder stays 
for tops of combustion chambers and back connections, or wherever 
used, shall be proportioned to conform to the following formula : 

cycd 2 ycT 

Maximum allowable working pressure = , w p\yn v w 

where 

W = extreme distance between supports, in. 

P = pitch of supporting bolts, in. 

D == distance between girders from center to center, in. 
d = depth of girder, in. 

T =■ thickness of girder, in. 

C = 7000 when the girder is fitted with one supporting bolt 

C = 10,000 when the girder is fitted with two or three sup- 
porting bolts 

C = 11,000 when the girder is fitted with four or five sup- 
porting bolts 

C = 11,500 when the girder is fitted with six or seven sup- 
porting bolts 

C = 12,000 when the girder is fitted with eight or more sup- 
porting bolts 

Example: Given IF — 31 in., P = 7.5 in., D = 7.75 in., 
d == 7.5 in., T = 2 in.; three stays per girder, C = 10,000; then 
substituting in formula: 

Maximum allowable working pressure — 

10,000X7.5X7.5X2 1<H M ,; 

(34-7.5) X 7.75X34 = 16L1 A " per Sq ' m " 

2'31 Maximum Allowable Working Pressure on Truncated Cones. 
Upper combustion chambers or vertical submerged tubular boilers 
made in the shape of a frustum of a cone when not over 38 in. diam- 
eter at the large end, may be used without stays if figured by the 
rule for plain cylindrical furnaces (Par. 239) making D in the for- 
mula equal to the diameter at the large end. When over 38 in. in 
diameter, that portion over 30 in. in diameter shall be fully supported 
by staybolts or gussets to conform to the provisions for the staying of 
flat surfaces. 

23& Stay Tubes. When stay tubes are used in multitubular 



NEW INSTALLATIONS, TART I, SECTION I, POWER BOILERS 59 

boilers to give support to the tube plates, the sectional area of such 
stay tubes may be determined as follows : 

Total section of stay tubes, sq. in. == — : — ?p 

where 

A = area of that portion of the tube plate containing the 

tubes, sq. in. 
a = aggregate area of holes in the tube plate, sq. in. 
P = maximum allowable working pressure, lb. per sq. in. 
T = working tensile stress allowed in the tubes, not to exceed 
7000 lb. per sq. in. 
,233 The pitch of stay tubes shall conform to the formula given 
in Par. 199, using the values of C as given in Table 6. 

TABLE 6. VALUES OF C FOR DETERMINING PITCH OF STAY TUBES. 



Pitch of Stay Tubes in the Bounding Rows 


When tubes 

have no Nuts 

Outside of Plates 


When tubes 

are Fitted with 

Nuts Outside 

of Plates 


Where there are two plain tubes between each stay tube .... 

Where there is one plain tube between each stay tube 

Where every tube in the bounding rows is a stay tube and 


120 
140 


130 
150 

170 







When the ends of tubes are not shielded from the action of flame or 
radiant heat, the values of C shall be reduced 20 per cent. The tubes 
shall project about % in. at each end and be slightly flared. Stay 
tubes when threaded shall not be less than 3/16 in. thick at bottom of 
thread ; nuts on stay tubes are not advised. For a nest of tubes C shall 
be taken as 140 and S as the mean pitch of stay tubes. For spaces be- 
tween nests of tubes S shall be taken as the horizontal distance from 
center to center of the bounding rows of tubes and C as given in 
Table 6. 

TUBE SHEETS OF COMBUSTION CHAMBERS 

234 The maximum allowable working pressure on a tube sheet 
of a combustion chamber, where the crown sheet is not suspended from 
the shell of the boiler, shall be determined by the following formula : 

(D—d) TX27,000 
r ~ WXD 



60 REPORT OF BOILER CODE COMMITTEE. AM.SOC.M.E. 

where 

P = maximum allowable working pressure, lb. per sq. in. 
D = least horizontal distance between tube centers, in. 
d = inside diameter of tubes, in. 
T = thickness of tube plate, in. 

W = distance from tube sheet to opposite combustion chamber 
sheet, in. 
Example: Eequired the working pressure of a tube sheet sup- 
porting a crown sheet braced by crown bars. Horizontal distance 
between centers, 4% in. ; inside diameter of tubes, 2.782 in. ; thickness 
of tube sheets, 11/16 in.; distance from tube sheet to opposite com- 
bustion chamber sheet, 34^4 in., measured from outside of tube plate 
to outside of back plate; material, steel. ^Substituting and solving: 
p (4.125—2.782) X0.6875X27,000 . _ _, 

P = ~ 34.25X4.125 = liQ lb ' P er s * m - 

235 Sling stays may be used in place of girders in all cases cov- 
ered in Par. 2,34, provided, however, that when such sling stays are 



^7777777777777? 




Fig. 17 Proper Location of Staybolts Adjacent to Longitudinal 
Joint in Furnace Sheet 

used, girders or screw stays of the same sectional area shall be used for 
securing the bottom of the combustion chamber to the boiler shell. 

23i6 When girders are dispensed with and the top and bottom 
of combustion chambers are secured by sling stays or braces, the sec- 
tional area of such stays shall conform with the requirements of rules 
for stays and stayed surfaces. 

237 Furnaces of Vertical Boilers. In a vertical fire-tube boiler 
the furnace length, for the purpose of calculating its strength and 
spacing staybolts over its surface, shall be measured from the center 
of rivets in the bottom of the water-leg to the center of rivets in the 
flange of the lower tube sheet. 

238 When the longitudinal joint of the furnace sheet of a vertical 
fire-tube boiler is of lap-riveted construction and staybolted, a stay- 
bolt in each circular row shall be located near the longitudinal joint, 
as shown in Fig. 17. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 61 

239 Plain Circular Furnaces. The maximum allowable working 
pressure for unstayed, riveted, seamless or lap welded furnaces, where 
the length does not exceed 6 times the diameter and where the thick- 
ness is at least 5/16 in. shall be determined by one or the other of the 
following formulae: 

a Where the length does not exceed 120 times the thickness of 
the plate 

P= 7,-{ (18.75XT)— (1.03X&) } 

1) Where the length exceeds 120 times the thickness of the plate 

4250 XT 2 



P = 



where 



LXB 



P = maximum allowable working pressure, lb. per sq. in. 

I) = outside diameter of furnace, in. 

L = length of furnace, in. 

T = thickness of furnace walls, in sixteenths of an inch. 

Where the furnaces have riveted longitudinal joints no deduction 

need be made for the joint provided the efficiency of the joint is greater 

than PXD divided by 1,250X2". 

Example. Given a furnace 26 in. in diameter, 94 in. long and 

% in. thick. The length exceeds 120 times the thickness of the plate, 

hence the formula (b) should be used. Substituting the values in 

this formula : 

p 4250X8X8 ._ ,, 
= — Q4V26 — = 111 lb. per sq. in. 

240 A plain cylindrical furnace exceeding 38 in. in diameter shall 

be stayed in accordance with the rules governing flat surfaces. 

.241 Circular Flues. The maximum allowable working pressure 

for seamless or welded flues more than 5 in. in diameter and up to and 

including 18 in. in diameter shall be determined by one or the other 

of the following formulae : 

a Where the thickness of the wall is less than 0.023 times the 

diameter 

10,000,000 XT 3 
L — D z 

b Where the thickness of the wall is greater than 0.023 times 
the diameter 



62 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

where 

P — maximum allowable working pressure, lb. per sq. in. 
D = outside diameter of flue, in. 
T = thickness of wall of flue, in. 
c The above formulae may be applied to riveted flues of the 
sizes specified provided the sections are not over 3 ft. in 
length and provided the efficiency of the joint is greater 
than PXD divided by 20,000XZ\ 
Example. Given a flue 14 in. in diameter and 5/16 in. thick. 
The thickness of the wall is less than 0.0/23 times the diameter ; hence 
the formula (a) should be used. Substituting the values in this 
formula : 

„ 10,000,000X5/16X5/16X5/16 

P = 1 4X14X11 = PeT Sq ' m ' 

242 Adam,son Type. When plain horizontal flues are made in 
sections not less than 18 in. in length, and not less than 5/16 in. thick : 
a They shall be flanged with a radius measured on the fire side, 
of not less than three times the thickness of the plate, and the flat 
portion of the flange outside of the radius shall be at least three times 
the diameter of the rivet holes. 

b The distance from the edge of the rivet holes to the edge of the 
flange shall be not less than the diameter of the rivet hole, and the 
diameter of the rivets before driving shall be at least % in- larger than 
the thickness of the plate. 

c The depth of the Adamson ring between the flanges shall be not 
less than three times the diameter of the rivet holes, and the ring shall 
be substantially riveted to the flanges. The fire edge of the ring shall 
terminate at or about the point of tangency to the curve of the flange, 
and the thickness of the ring shall be not less than y 2 in. 

The maximum allowable working pressure shall be determined by 
the following formula : 

P== "TT { (is-raxz")— (i.08xi) } 

where 

P = maximum allowable working pressure, lb. per sq. in, 

D = outside diameter of furnace, in. 

L = length of furnace section, in. 

T = thickness of plate, in sixteenths of an inch. 
Example. Given a furnace 44 in. in diameter, 48 in. in length, 
and V2 m - thick. Substituting values in formula : 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 63 

P= ^~ { (18.75X8) — (1.03X48) | 
= 1.309 (150—49.44) = 131 lb. per sq. in. 

243 The maximum allowable working pressure on corrugated 
furnaces, such as the Leeds suspension bulb, Mori son, Fox, Purves, or 
Brown, having plain portions at the ends not exceeding 9 in. in length 
(except flues especially provided for) when new and practically circu- 
lar, shall be computed as follows : 

P OXT 
1 - D 

where 

P = maximum allowable working pressure, lb. per sq. in. 

T = thickness, in. — not less than 5/16 in. for Leeds, Morison, 
Fox and Brown, and not less than 7/16 in. for Purves 
and other furnaces corrugated by sections not over 18 
in. long. 

D — mean diameter, in. 

= 17,300, a constant for Leeds furnaces, when corrugations 
are not more than 8 in. from center to center and not 
less than 2 1 4 m - deep. 

C = 15,600, a constant for Morison furnaces, when corruga- 
tions are not less than 8 in. from center to center and 
the radius of the outer corrugations is not more than 
one half that of the suspension curve. 

C = 14,000, a constant for Fox Furnaces, when corrugations 
are not more than 8 in. from center to center and not 
less than 1% in. deep. 

C = 14,000, a constant for Purves furnaces when rib projec- 
tions are not more than 9 in. from center to center and 
not less than 1% in. deep. 

C = 14,000, a constant for Brown Furnaces, when corrugations 
are not more than 9 in. from center to center and not 
less than 1% in. deep. 

C ~ 10,000, a constant for furnaces corrugated by sections not 
more than 18 in. from center to center and not less 
than 21/0 in. deep, measured from the least inside to 
the greatest outside diameter of the corrugations, and 
having the ends fitted one into the other and substan- 
tially riveted together, provided that the plain parts 
at the ends do not exceed 12 in. in length. 



64 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E'. 

In calculating the mean diameter of the Morison furnace, the least 
inside diameter plus 2 in., may be taken as the mean diameter. 

244 The thickness of a corrugated or ribbed furnace shall be as- 
certained by actual measurement. The furnace shall be drilled for a 
y±-m. pipe tap and fitted with a screw plug that can be removed for 
the purpose of measurement. For the Brown and Purves furnaces, the 
holes shall be in the center of the second flat; for the Morison, Fox 
and other similar types, in the center of the top corrugation, at least 
as far in as the fourth corrugation from the end of the furnace. 

245 Cast Iron Headers. The pressure allowed on a water-tube 
boiler, the tubes of which are secured to cast-iron or malleable-iron 
headers, shall not exceed 160 lb. j:>er sq. in. The form and size of the 
internal cross section of a cast-iron or malleable-iron header at any 
point shall be such that it will fall within a 6 in. by 7 in. rectangle. 

246 The cast-iron used for the headers of water-tube boilers shall 
conform with the Specifications for Gray-iron Castings given in Pars. 
95 to 110, the header to be arbitrarily classified as a "medium casting" 
as to physical properties and tests, and as a "light casting" as to 
chemical properties. 

247 A east-iron header when tested to destruction, shall withstand 
a hydrostatic pressure of at least 1200 lb. per sq. in. A hydrostatic 
test at 400 lb. per sq. in. gage pressure shall be made on ali new 
headers with tubes attached. 

Tubes 

248 Tube Holes and Ends. Tube holes shall be drilled full size 
, from the solid plate, or they may be punched at least y 2 in. smaller 

in diameter than full size, and then drilled, reamed or finished full 
size with a rotating cutter. 

249 The sharp edges of tube holes shall be taken off on both sides 
of the plate with a file or other tool. 

250 A fire-tube boiler shall have the ends of the tubes substan- 
tially rolled and beaded, or welded at the firebox or combustion cham- 
ber end. 

251 The ends of all tubes, suspension tubes and nipples shall be 
flared not less than i/ s in. over the diameter of the tube hole on all 
water- tube boilers and superheaters, or they may be beaded. 

252 The ends of all tubes, suspension tubes and nipples of water- 
tube boilers and superheaters shall project through the tube sheets or 
headers not less than 14 in. nor more than y 2 in. before flaring. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 65 

ElVETING 

£53 Riveting. Rivet holes, except for attaching stays or angle 
bars to heads, shall be drilled full size with plates, butt straps and 
heads bolted in position ; or they may be punched not to exceed Vi in. 
less than full diameter for plates over 5/16 in. in thickness, and % in. 
less than full diameter for plates not exceeding 5/16 in. in thickness, 
and then drilled or reamed to full diameter with plates, butt straps 
and heads bolted in position. 

254 After drilling rivet holes, the plates and butt straps shall be 
separated and the burrs removed. 

2-55 Rivets. Rivets shall be of sufficient length to completely fill 
the rivet holes and form heads at least equal in strength to the bodies 
of the rivets. 

256 Rivets shall be machine driven wherever possible, with suffi- 
cient pressure to fill the rivet holes, and shall be allowed to cool and 
shrink under pressure. 

Calking 

2 r« 7 Calling. The calking edges of plates, butt straps and heads 
shall be beveled. Every portion of the calking edges of plates, butt 
straps and heads shall be planed, milled or chipped to a depth of not 
less than % in. Calking shall be done with a round-nosed tool. 

Manholes 

258 Manholes. An elliptical manhole opening shall be not less 
than 11 X 15 in. or 10 X 16 in. in size. A circular manhole opening 
shall be not less than 15 in. in diameter. 

259 A manhole reinforcing ring when used, shall be of steel or 
wrought-iron, and shall be at least as thick as the shell plate. 

260 Manhole frames on shells or drums when used, shall have the 
proper curvature, and on boilers over 48 in. in diameter shall be riveted 
to the shell or drum with two rows of rivets, which may be pitched as 
shown in Fig. 18. The strength of the rivets in shear on manhole 
frames and reinforcing rings shall be at least equal to the tensile 
strength of that part of the shell plate removed, on a line parallel to 
the axis of the shell, through the center of the manhole, or other 
opening. 



60 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



2-61 The proportions of manhole frames and other reinforcing 
rings to conform to the above specifications may be determined by the 
use of the following formulae, which are based on the assumption that 
the rings shall have the same tensile strength per square inch of sec- 
tion as, and be of not less thickness than, the shell plate removed. 



For a single-riveted ring: W 



For a double-riveted ring : W 



2Xt 

iXk 

2Xt 



+« 



+2d 




Fig. 18 Method of Biveting Manhole Frames to Shells or 
Drums with Two Eows of Eivets 



For two single-riveted rings : W = 



IXk 



±xt 
ixk 



d 



±xt 



+2d 



For two double-riveted rings : W 

Where 

W = least width of reinforcing ring, in. 
t x = thickness of shell plate, in. 
d = diameter of rivet when driven, in. 
t = thickness of reinforcing ring — not less than thickness of 

the shell plate, in. 
T = tensile strength of the ring, lb. per sq. in. of section 
a = net section of one side of the ring or rings, sq. in. 
S = shearing strength of rivet, lb. per sq. in. of section (see 

Par. 16) 



NEW INSTALLATIONS, PART T, SECTION I, POWER BOILERS 67 

I — length of opening in shell in direction parallel to axis of 
shell, in. 
N = number of rivets 
To find the number of rivets for a single or double reinforcing ring: 

AT= 5.1X^X0 



SXd 2 

,26,2 Manhole plates shall be of wrought steel or shall be steel 
castings. 

263 The minimum width of bearing surface, for a gasket on a 
manhole opening shall be % in. No gasket for use on a manhole or 
handhole of any boiler shall have a thickness greater than 14 in. 

264 A manhole shall be located in the front head, below the 
tubes, of a horizontal return tubular boiler 48 in. or over in diameter. 
Smaller boilers shall have either a manhole or a handhole below the 
tubes. There shall be a manhole in the upper part of the shell or head 
of a fire-tube boiler over 40 in. in diameter, except a vertical fire-tube 
boiler, or except 0.1 internally fired boilers not over 48 in. in diameter. 
The manhole maj be placed in the head of the dome. Smaller boilers 
shall have either i manhole or a handhole above the tubes. 



Washout Holes 

265 A traction, portable or stationary boiler of the locomotive 
type shall have not less than six handholes, or washout plugs, located 
as follows: one in the rear head below the tubes; one in the front 
head at or about the line of the crown sheet ; four in the lower part of 
the waterleg; also, Where possible, one near the throat sheet. 

266 A vertical fire-tube boiler, except the boiler of a steam fire- 
engine, shall have not less than seven handholes, located as follows : 
three in the shell at or about the line of the crown sheet ; one in the 
shell at or about the line of the fusible plug when used; three in the 
shell at the lower part of the waterleg. A vertical fire-tube boiler, sub- 
merged tube type, shall have two or more handholes in the shell, in 
line with the upper tube sheet. 

267 A vertical fire-tube boiler of a steam fire-engine shall have at 
least three brass washout plugs of not less than 1-in. iron pipe size, 
screwed into the shell and located as follows : one at or about the line 
of the crown sheet ; two at the lower part of the waterleg. 



68 report of boiler code committee, am.soc.m.e. 

Theeaded Openings 

268 Threaded Openings. An opening in a boiler for a threaded 
pipe connection 1 in. in diameter or over shall have not less than the 
number of threads given in Table 7. 



TABLE 7 MINIMUM NUMBER OF PIPE THREADS FOR CONNECTIONS TO 

BOILERS 



Size of pipe connec- 


1 and 1M 


1H and 2 


2)4 to 4 
inclusive 


4^ to 6 
inclusive 


7 and 8 


9 and 10 


12 






Number of threads 


11^ 


ny 2 


8 


8 


8 


8 


8 






Minimum number of 
threads required in 


4 


5 


7 


8 


10 


12 


13 






Minimum thickness 
of material re- 
quired to give above 
number of threads, 


0.348 


0.435 


0.875 


1 


1.25 


1.5 


1.625 







If the thickness of the material in the boiler is not sufficient to give 
such number of threads, there shall be a pressed steel flange, bronze 
composition flange, steel-cast flange or steel plate, so as to give the re- 
quired number of threads, constructed and riveted to the boiler in ac- 
cordance with methods given in Par. 261. A steam main or safety 
valve opening may be fitted with either a steel cast, wrought-steel or 
bronze composition nozzle. A feed-pipe connection may be fitted with 



a brass or steel boiler bushing. 



Safety Yalves 



269 Safety Valve Requirements. Each boiler shall have two or 
more safety valves, except a boiler for which one safety valve 3 -in. size 
or smaller is required by these Eules. 

270 The safety valve capacity for each boiler shall be such that 
the safety valve or valves will discharge all the steam that can be 
generated by the boiler without allowing the pressure to rise more 
than six per cent above the maximum allowable working pressure, or 
more than six per cent above the highest pressure to which any valve 
is set. 

271 One or more safety valves on every boiler shall be set at or 
below the maximum allowable working pressure. The remaining 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 09 

valves may be set within a range of three per cent above the maximum 
allowable working pressure, but the range of setting of all of the 
valves on a boiler shall not exceed ten per cent of the highest pressure 
to which any valve is set. 

272 .Safety valves shall be of the direct spring loaded pop type 
with seat and bearing surface of the disc either inclined at an angle 
of about 45 deg. or flat at an angle of about 90 cleg, to the center 
line of the spindle. The vertical lift of the valve disc measured 
immediately after the sudden lift due to the pop may be made any 
amount desired up to a maximum of 0.15 in. irrespective of the size 
of the valve. The nominal diameter measured at the inner edge of 
the valve seat shall be not less than 1 in. or more than 4% i n - 

273 Each safety valve shall have plainly stamped or cast on the 
body: 

a The name or identifying trade-mark of the manufacturer 

b The nominal diameter with the words "Bevel Seat" or "Flat 
.Seat" 

c The steam pressure at which it is set to blow 

d The lift of the valve disc from its seat, measured immedi- 
ately after the sudden lift due to the pop 

e The weight of steam discharged in pounds per hour at the 
pressure for which it is set to blow. 

274 The minimum capacity of a safety valve or valves to be 
placed on a boiler shall be determined on the basis of 6 lb. of steam 
per hour per sq. ft. of boiler heating surface for water tube boilers, 
and 5 lb. for all other types of power boilers, and upon the relieving 
capacity marked on the valves by the manufacturer, provided such 
marked relieving capacity does not exceed that given in Table 8. In 
case the relieving capacity marked on the valve or valves exceeds the 
maximum given in Table 8, the minimum safety valve capacity shall 
be determined on the basis of the maximum relieving capacity given in 
Table 8 for the particular size of valve and working pressure for 
which it was constructed. The heating surface shall be computed 
for that side of the boiler surface exposed to the products of com- 
bustion, exclusive of the superheating surface. In computing the 
heating surface for this purpose only the tubes, shells, tube sheets 
and the projected area of headers need be considered. 



TABLE 8 DISCHARGE CAPACITIES FOR DIRECT SPRING-LOADED POP SAFETY VALVES, 

WITH 45 DEG. BEVEL SEATS 



Gage 
Pres., 
Lb. per 
Sq.In. 




Diameter, 1 In. 


Diameter, 1}4, In. 


Diameter, 1*4 In. 


Min. 


Int. 


Max. 


Min. 


Int. 


Max. 


Min. 


Int. 


Max. 


15 


Lift, in. . . 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


95,500 


191,000 


238,900 


179,200 


238,800 


293,500 


214,900 


358,300 


429,900 


Lb. hr 


65 


131 


163 


122 


163 


203 


146 


245 


293 


25 


Lift, in. .. 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


127,700 


255,400 


319,300 


239,500 


319,300 


399,100 


287,400 


478,900 


574,700 


Lb. hr 


87 


174 


218 


164 


218 


272 


196 


326 


392 


50 


Lift, in. . . 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


208,200 


416,400 


520,400 


390,300 


520,400 


650,500 


468,300 


780,600 


936,600 


Lb. hr 


142 


284 


354 


266 


354 


444 


320 


532 


639 


75 


Lift, in ... . 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


288,600 


577,200 


721,400 


541,100 


721,400 


901,800 


649,300 


1,082,000 


1,299,000 


Lb. hr 


197 


393 


492 


369 


492 


615 


443 


738 


886 


100 


Lift, in 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH....... 


369,000 


738,000 


922,500 


691,900 


922,500 


1,153,000 


830,300 


1,384,000 


1,661,000 


Lb. hr 


252 


503 


629 


472 


629 


78C 


566 


944 


1133 


125 


Lift, in ... . 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


449,400 


898,900 


1,124,000 


842,700 


1,124,000 


1,404,000 


1,011,000 


1,685,000 


2,022,000 


Lb. hr 


307 


613 


767 


575 


767 


957 


689 


1149 


1379 


150 


Lift, in 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH....... 


529,900 


1,060,000 


1,325,000 


993,500 


1,325,000 


1,656,000 


1,192,000 


1,987,000 


2,384,000 


Lb. hr 


362 


723 


904 


677 


904 


1129 


813 


1355 


1625 


175 


Lift, in 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


610,300 


1,221,000 


1,526,000 


1,144,000 


1,526,000 


1,907,000 


1,373,000 


2,289,000 


2,746,000 


Lb. hr 


416 


833 


1040 


780 


1040 


1301 


936 


1561 


1872 


200 


Lift, in 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


690,700 


1,381,000 


1,727,000 


1,295,000 


1,727,000 


2,158,000 


1,554,000 


2,590,000 


3,108,000 


Lb. hr 


471 


941 


1178 


883 


1178 


1472 


1060 


1766 


2119 


225 


Lift, in 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


771,100 


1,542,000 


1,928,000 


1,446,000 


1,928,000 


2,410,000 


1,735,000 


2,892,000 


3,470,000 


Lb. hr 


526 


1052 


1315 


986 


1315 


1643 


1183 


1972 


2366 


250 


Lift, in 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


851,600 


1,703,000 


2,129,000 


1,597,000 


2,129,000 


2,661,000 


1,916,000 


3,193,000 


3,832,000 


Lb. hr 


581 


1161 


1451 


1089 


1451 


1814 


1307 


2177 


261S 


275 


Lift, in. ... . 


0.02 


0.C4 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


932,000 


1,864,000 


2,330,000 


1,748,000 


2,330,000 


2,913,000 


2,097,000 


3,495,000 


4,194,000 


Lb. hr 


635 


1271 


1589 


1192 


1589 


1986 


1430 


2383 


2860 


300 


Lift, in. . . . 


0.02 


0.04 


0.05 


0.03 


0.04 


0.05 


0.03 


0.05 


0.06 


CH 


1,024,000 


2,048,000 


2,531,000 


1,898,000 


2,531,000 


3,164,000 


2,278,000 


3,797,000 


4,556,000 


Lb. hr 


698 


1397 


1746 


1294, 


1726 


2157 


1553 


2589 


3107 



The Discharge capacity of a Flat Seat Valve of a given diameter with a given lift may be obtained by multiplying 
the discharge capacity given in the Table for a 45 deg. bevel seat valve of same diameter and same lift, by 1.4. 

70 



TABLE 8 (Continue) DISCHARGE CAPACITIES FOR DIRECT SPRING-LOADED POP 
TABL ^ ONTINU S ^ FETY VALVES , WITH 45 DEG. BEVEL SEATS 



Gage 
Pree., 



Lift, in. .. 



15 



Lb. br 



25 



50 



'H. 



Lift. in. 



CH. 



Lb. hr. 



Lift, in . . 



CH. 



Diameter, 2 In. 



Min. 



0.04 



382,200 



2G1 



0.04 



510,900 



349 



0.04 



832,600 



Lb. hr. 



Lift, in. 



75 



CH.... 



100 



568 



Lb. hr. 



Lift, in. 



CH. 



Lb.hr. 



Lift, in. 



125 



CH. 



Lb. hr. 



150 



175 



0.04 



Int. 



0.06 
573,300 



391 



0.06 



766,300 



523 



0.06 



1,249,000 



851 



0.06 



1,154,000 



Max. 



0.07 



668,900 



456 



0.07 



894,000 



610 



0.07 



1,457,000 



994 



0.07 



1,731,000 



787 



0.04 



1,476,000 



2,214,G00 



1007 



0.04 



1,795,000 



Lift, in. 



1224 



0.04 



CH 2,109,0003,179,000 



Lb. hr. 



,ift, in. 



CH.. 



2,441,0003,662,000 



Lb. hr. 



Lift, in. 



200 



CH. 



Lb.hr. 



Lift, in. 



225 



CH. 



Lb.hr. 



250 



275 



Lift, in. 



CH. 



Lb.hr. 



Lift, in. 



CH. 



1438 



0.04 



2,020,000 



1181 



0.06 



1510 



0.06 



1377 



Diameter, 2^ In. 



Min. 



0.04 



477,700 



326 



0.04 



638,500 



435 



0.04 



1,041,000 



Int. 



0.06 



716,600 



488 



0.06 



957,900 



653 



0.06 



1,561,000 



710 



0.04 



1064 



0.06 



Max. 



0. 



955,500 



651 



0.08 



1,277,000 



871 



0.08 



2,081,000 



14] 



Diameter, 3 In. 



Min. 



0.05 



716,600 



489 



0.05 



957,900 



653 



0.05 



1,561,000 



1,443,000 



2,164,000 



0.07 



2,583,000 



1761 



984 



0.04 



1,845,000 



0.07 



5,000 



3,146,000 



1836 



0.06 



3,709,000 



2158 



0.06 



1664 



0.04 



2,763,000 



4,144,000 



1884 



0.04 



3,085,000 



2104 



0.04 



3,406,000 



232! 



2497 



0.06 



2145 



0.07 



2529 



0.07 



1258 



0.04 



2,247,000 



1532 



0.04 



2,649,000 



1475 



0.06 



0.08 



2,886,000 



1968 



0.08 



2,768,000 



1887 



0.06 



3,371,000 



2299 



0.06 



3,974,000 



1806 



0.04 



4,272,0003,051,000 



2913 



0.07 



2826 



0.06 



4,626,000 



5,398,000 



3154 



0.06 



5,109,000 



3484 



0.04 



3,728,000 



Lb.hr.. 



300 



Lift, in. 



CH. 



Lb.hr. 



2542 



0.04 



4,050,000 



2762 



0.06 



5,592,000 



3813 



2081 



0.04 



2710 



0.06 



4,577,000 



3121 



3,690,000 



2516 



0.08 



4,494,000 



1064 



0.05 



Int. 



0.08 



1,147,000 



782 



0.08 



1,533,000 



1046 



0.08 



2,498,000 



1703 



2,164,000 



1475 



0.05 



0.08 



Max. 



0.10 



1,433,000 



977 



0.10 



1,916,000 



1307 



0.10 



3,122,000 



2129 



0.10 



3,463,000 



2361 



0.08 



4,329,000 



2951 



0.10 



2,768,000 



1887 



0.05 



3,371,000 



3064 



0.08 



5,299,000 



3613 



0.08 



6,103,000 



4161 



0.06 



4,835,000 3,454,000 5,180,000 



3296 



0.07 



3,856,000 



3680 



0.07 



5,961,0004,258,000 



4064 



0.07 



,524,000 



0.06 



,075,000 



4143 



4448 



0.07 



7,087,000 



2354 



0.04 



2629 



0.04 



2903 



0.04 



4,660,000 



3177 



0.08 



2299 



0.05 



3,974,000 



2710 



0.05 



4,577,000 



3121 



0.05 



4,428,000 



3019 



0.08 



5,393,000 



3677 



0.08 



,358,000 



4335 



7,323,000 



4993 



6,907,000 



3532 



0.06 



5,784,000 



3944 



0.06 



,387,000 



4355 



0.06 



5,990,000 



4766 



0.04 



5,062,000 



4832 



3452 



0.06 



7,593,000 



5177 



4709 



0.08 



7,711,000 



5258 



0.08 



8,516,000 



5807 



0.08 



9,320,000 



6355 



0.08 



10,124,000 



6903 



5,180,000 



3532 



0.05 



5,784,000 



3944 



0.05 



6,387,000 



4355 



0.05 



,990,000 



4766 



0.05 



0.( 



5,535,000 



3774 



0.10 



,741,000 



4596 



0.10 



7,948,000 



5419 



0.10 



9,154,000 



6242 



0.10 



8,289,000 



10,361,000 



5651 



0.08 



9,254,000 



11,567,000 



6310 



0.08 



10,219,000 



6968 



0.08 



11,180,000 



7620 



7,593,000 



5177 



0.08 



12.149,000 



8280 



7064 



0.10 



7890 



0.10 



12,774,000 



8708 
0.10 



13,980,000 



9533 



0.10 



15,186,000 



10,358 



"TZ — ^T — T ;+,^f q Flat Spat, Valve of a eiven diameter with a given lift may be obtained by multiplying 

I^R^^f^^J^/AhASje for a 45 del bevel seat valve of same diameter and same lift, by 1.4. 

This table is concluded on the fottovring pagi, 
71 



1 he JJiscnarge capacity m <* ^ ia, X, rr i /=£„ 

the discharge capacity given in the Table for a 4o deg. 



TABLE 8 (Concluded) DISCHARGE CAPACITIES FOR DIRECT SPRING-LOADED POP SAFETY 
VALVES, WITH 45 DEG. BEVEL SEATS 



Gage 
Pres., 
Lb. pr-r 
Sq. In. 




Diameter, 3>6 In. 


Diameter, 4 In. 


Diameter, 4 J^ In. 


) 


Min. 


Int. 


Max. 


Min. 


■ Int. 


Max. 


Min. 


Int. 


Max. 




15 


Lift, in 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


1,003,000 


1,505,000 


1,839,000 


1,338,000 


1,911,000 


2,293,000 


1,720,000 


2,365,000 


2,795,000 




Lb.hr 


684 


1026 


1254 


912 


1303 


1564 


1173 


1613 


1906 




25 


Lift, in. . . . 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


1,341,000 


2,012,000 


2,459,000 


1,788,000 


2,554,000 


3,065,000 


2,299,000 


3,161,000 


3,736,000 




Lb. hr 


914 


1372 


1676 


1219 


1742 


2090 


1568 


2156 


2547 




50 


Lift, in 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


2,186,000 


3,278,000 


4,007,000 


2,914,000 


4,163,000 


4,996,000 


3,747,000 


5,152,000 


6,088,000 




Lb. hr 


1490 


2235 


2732 


1987 


2839 


3406 


2555 


3513 


4151 




75 


Lift, in. . . . 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


Q.08 


0.11 


0.13 




CH 


3,030,000 


4,545,000 


5,555,000 


4,040,000 


5,772,000 


6,926,000 


5,194,000 


7,142,000 


8,441,000 




Lb. hr 


2066 


3099 


3788 


2754 


3935 


4722 


• 3542 


4870 


5756 




100 


Lift, in 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


3,875,000 


5,812,000 


7,103,000 


5,166,000 


7,380,000 


8,856,000 


6,642,000 


9,133,000 


10,793,000 




Lb. hr 


2642 


3963 


4843 


3522 


5032 


6038 


4529 


6227 


7358 




125 


Lift, in. . . . 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


4,719,000 


7,079,000 


8,652,000 


6,292,000 


8,988,000 


10,786,000 


8,089,000 


11,123,000 


13,146,000 




Lb.hr 


3218 


4826 


5899 


4290 


0128 


7354 


5516 


7583 


8963 




150 


Lift, in. . . . 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


5,564,000 


8,345,000 


10,199,000 


7,418,000 


10,597,000 


12,717,000 


9,537,000 


13,114,000 


15,498,000 




Lb. hr 


3794 


5690 


6954 


5058 


7226 


8670 


6503 


8940 


10566 




175 


Lift, in. . . . 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


6,408,000 


9,612,000 


11,748,000 


8,544,000 


12,206,000 


14,647,000 


10,985,000 


15,105,000 


17,851,000 




Lb. hr 


4369 


6553 


8010 


5824 


8320 


9984 


7490 


10298 


1217c 




200 


Lift, in ... . 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


7,253,000 


10,879,000 


13,296,000 


9,670,000 


13,814,000 


16,580,000 


12,433,000 


17,095,000 


20,204,000 




Lb. hr 


4946 


7418 


9068 


6593 


9420 


11305 


8475 


11655 


13773 




225 


Lift, in 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


8,097,000 


12,146,000 


14,845,000 


10,796,000 


15,423,000 


18,507,000 


13,881,000 


19,086,000 


22,556,000 




Lb. hr 


5521 


8280 


10120 


7361 


10514 


12616 


9465 


13013 


15383 




250 


Lift, in. . . . 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


8,942,000 


13,412,000 


16,393,000 


11,922,000 


17,031,000 


20,438,000 


15,328,000 


21,076,000 


24,908,000 




Lb. hr 


6097 


9143 


11175 


8130 


11614 


13938 


10448 


14366 


16980 




275 


Lift, in 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH.. 


9,786,000 


14,679,000 


17,941,000 


13,048,000 


18,640,000 


22,368,000 


L6,776,000 


23,067,000 


27,261,000 




Lb. hr. . . . 


6672 


10005 


12233 


8895 


12707 


15248 


11438 


15728 


1858£ 




300 


Lift, in. ... 


0.06 


0.09 


0.11 


0.07 


0.10 


0.12 


0.08 


0.11 


0.13 




CH 


10,630,000 


15,946,000 


19,489,000 


14,174,000 


20,249,000 


24,298,000 


18,224,000 


25,058,000 


29,614,000 




Lb. hr 


7248 


10875 


13290 


9668 


13807 


16568 


12428 


17088 


20195 




The 
the disch 


Discharge c 
arge capacit 


apacity of < 
y given in 


i Flat Seat 
the Table f 


Valve of a 
or a 45 deg 


given dian 
. bevel seat 


teter with a 
valve of sj 


given lift ] 
ime diamel 


■nay be obt 


ained by rr 


mltiplying 

14 





72 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 73 

275 .Safety valve capacity may be checked in any one of three 
different ways, and if found sufficient, additional capacity need not be 
provided : 

a By making an accumulation test, by shutting off all other 
steam discharge outlets from the boiler and forcing the 
fires to the maximum. The safety valve equipment shall 
be sufficient to prevent an excess pressure beyond six per 
cent as specified in Par. 270. 

b By measuring the maximum amount of fuel that can be 
burned and computing the corresponding evaporative ca- 
pacity upon the basis of the heating value of the fuel. See 
Appendix, Pars. 421 to 427. 

c By determining the maximum evaporative capacity by 
measuring the feed water. The sum of the safety valve 
capacities marked on the valves, shall be equal to or greater 
than the maximum evaporative capacity of the boiler. 

276 When two or more safety valves are used on a boiler, they 
may be either separate or twin valves made by mounting individual 
valves on Y-bases, or duplex, triplex or multiplex valves having two 
or more valves in the same body casing. 

277 The safety valve or valves shall be connected to the boiler 
independent of any other steam connection, and attached as close as 
possible to the boiler, without any unnecessary intervening pipe or 
fitting. Every safety valve shall be connected so as to stand in an up- 
right position, with spindle vertical, when possible. 

278 Each safety valve shall have full sized direct connection to 
the boiler. No valve of any description shall be placed between the 
safety valve and the boiler, nor on the discharge pipe between the 
safety valve and the atmosphere. When a discharge pipe is used, it 
shall be not less than the full size of the valve, and shall be fitted 
with an open drain to prevent water from lodging in the upper part of 
the safety valve or in the pipe. 

279 If a muffler is used on a safety valve it shall have sufficient 
outlet area to prevent back pressure from interfering with the proper 
operation and discharge capacity of the valve. The muffler plates or 
other devices shall be so constructed as to avoid any possibility of re- 
striction of the steam passages due to deposit. When an elbow is 
placed on a safety valve discharge pipe, it shall be located close to the 
safety valve outlet or the pipe shall be securely anchored and supported. 
All safety valve discharges shall be so located or piped as to be carried 



74 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

clear from running boards or working platforms used in controlling the 
main stop valves of boilers or steam headers. 

280 When a boiler is fitted with two or more safety valves on one 
connection, this connection to the boiler shall have a cross-sectional 
area not less than the combined area of all of the safety valves with 
which it connects. 

281 ,Safety valves shall operate without chattering and shall be 
set and adjusted as follows : To close after blowing down not more 
than 4 lb. on boilers carrying an allowed pressure less than 100 lb. 
per sq. in. gage. To close after blowing down not more than 6 lb. on 
boilers carrying pressures between 100 and 200 lb. per sq. in. gage 
inclusive. To close after blowing down not more than 8 lb. on boilers 
carrying over 200 lb. per sq. in. gage. 

282 Each safety valve used on a boiler shall have a substantial 
lifting device, and shall have the spindle so attached that the valve 
disc can be lifted from its seat a distance not less than one-tenth of 
the nominal diameter of the valve, when there is no pressure on the 
boiler. 

283 The seats and discs of safety valves shall be of non-ferrous 
material. 

284 Springs used in safety valves shall not show a permanent set 
exceeding 1/32 in. ten minutes after being released from a cold com- 
pression test closing the spring solid. 

285 The spring in a safety valve shall not be used for any 
pressure more than 10 per cent above or below that for which it was 
designed. 

28G A safety valve over 3-in. size, used for pressures greater than 
15 lb. per sq. in. gage, shall have a flanged inlet connection. The 
dimensions of the flanges shall conform to the American standard 
given in Tables 15 and 16 of the Appendix. 

287 When the letters A 8 M E Std are plainly stamped or cast 
on the valve body this shall be a guarantee by the manufacturer that 
the valve conforms with the details of construction herein specified. 

288 Every superheater shall have one or more safety valves near 
the outlet. The discharge capacity of the' safety valve or valves on 
an attached superheater may be included in determining the number 
and sizes of the safety valves for the boiler, provided there are no in- 
tervening valves between the superheater safety valve and the boiler. 

289 Every safety valve used on a superheater, discharging super- 
heated steam, shall have a steel body with a flanged inlet connection, 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 75 

and shall have the seat and disc of nickel composition or equivalent 
material, and the spring fully exposed outside of the valve casing so 
that it shall be protected from contact with the escaping steam. 

290 Every boiler shall have proper outlet connections for the 
required safety valve or valves, independent of any other steam outlet 
connection or of any internal pipe in the steam space of the boiler, the 
area of opening to be at least equal to the aggregate area of all of the 
safety valves to be attached thereto. 

Water and Steam Gages 

291 Water Glasses and Gage Cocks. Each boiler shall have at 
least one water glass, the lowest visible part of which shall be not less 
than 2 in. above the lowest permissible water level. 

292 No water glass connection shall be fitted with an automatic 
shut-off valve. 

,293 When shut-offs are used on the connections to a water 
column, they shall be either outside screw and yoke type gate valves 
or stop cocks with levers permanently fastened thereto, and such 
valves or cocks shall be locked or sealed open. 

294 Each boiler shall have three or more gage cocks, located 
within the range of the visible length of the water glass, except when 
such boiler has two water glasses with independent connections to the 
boiler and located on the same horizontal line and not less than 2 ft. 
apart. 

295 No outlet connections, except for damper regulator, feed- 
water regulator, drains or steam gages, shall be placed on the pipes 
connecting a water column to a boiler. 

296 Steam Gages. Each boiler shall have a steam gage con- 
nected to the steam space or to the water column or its steam connec- 
tion. The steam gage shall be connected to a syphon "or equivalent 
device of sufficient capacity to keep the gage tube filled with water 
and so arranged that the gage cannot be shut off from the boiler 
except by a cock placed near the gage and provided with a tee or lever 
handle arranged to be parallel to the pipe in which it is located when 
the cock is open. Connections to gages shall be of brass, copper or 
bronze composition. 

297 The dial of the steam gage shall be graduated to not less 
than iy 2 times the maximum allowable working pressure on the boiler. 

298 Each boiler shall be provided with a %-in. pipe size valved 



76 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

connection for attaching a test gage when the boiler is in service, so 
that the accuracy of the boiler steam gage can be ascertained. 

Fittings and Appliances 

299 Nozzles and Fittings. All fittings shall conform to the 
American Standards given in Tables 15 or 16 of the Appendix. 
Where the maximum allowable working pressure is less than 125 lb. 
per sq. in., 'Table 15 shall be used and where higher, Table 16. 

300 The minimum number of threads that a pipe or fitting shall 
screw into a tapped hole shall correspond to the numerical values 
given for number of threads in Table 7. 

301 Stop Valves. Each steam discharge outlet over 2 in. in di- 
ameter, except safety valve and superheater connections, shall be fitted 
with a stop valve or valves of the outside screw and yoke type, located 
as near the boiler ?s practicable. 

302 The main stop valves of boilers shall be extra heavy when 
the maximum allowable working pressure exceeds 125 lb. per sq. in. 
The fittings between the boiler and such valve or valves shall be extra 
heavy, as specified in Table 16 of the Appendix. 

303 When two or more boilers are connected to a common steam 
main, two stop valves, with an ample free blow drain between them, 
shall be placed in the steam connection between each boiler and the 
steam main. The discharge of this drain valve must be visible to the 
operator while manipulating the valve. The stop valves shall consist 
preferably of one automatic non-return valve (set next the boiler) 
and a second valve of the outside screw and yoke type; or, two valves 
of the outside screw and yoke type may be used. 

304 When a stop valve is so located that water can accumulate, 
ample drains shall be provided. 

305 Steam Mains. Provisions shall be made for the expansion 
and contraction of steam mains connected to boilers, by providing 
substantial anchorage at suitable points, so that there shall be no 
undue strain transmitted to the boiler. >Steam reservoirs shall be used 
on steam mains when heavy pulsations of the steam currents cause 
vibration of the boiler shell plates. 

306 Each superheater shall be fitted with a drain. 

307 Blow-off Piping. The size of a surface blow-off pipe shall 
not exceed IV2 m -> an( i it shall be carried through the shell or head 
with a brass or steel boiler bushing. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 77 

308 Each boiler shall have a bottom blow-off pipe, fitted with a 
valve or cock, in direct connection with the lowest water space prac- 
ticable ; the minimum size of pipe and fittings shall be 1 in. and the 
maximum size shall be 21/2 m - Globe valves shall not be used on 
such connections. 

309 A bottom blow-off cock shall have the plug held in place by 
a guard or gland. The end of the plug shall be distinctly marked in 
line with the passage. 

310 The blow-off pipe or pipes shall be extra heavy from boiler 
to valve or valves, and shall run full size without reducers or bushings. 
All fittings between the boiler and valves shall be of steel. 

311 When the maximum allowable working pressure exceeds 125 
lb. per sq. in., the bottom blow-off pipe shall have two valves, or a valve 
and a cock, and such valves, or valve and cock, shall be extra heavy, 
except that on a boiler having multiple blow-off pipes, a single master 
valve may be placed on the common blow-off pipe from the boiler, in 
which case only one valve on each individual blow-off is required. 

312 A bottom blow-off pipe when exposed to direct furnace heat 
shall be protected by fire-brick, a substantial cast-iron removable 
sleeve or a covering of non-conducting material. 

313 An opening in the boiler setting for a blow-off pipe shall be 
arranged to provide for free expansion and contraction. 

314: Feed Piping. The feed pipe of a boiler shall have an open 
end or ends. Wherever globe valves are used on feed piping, the inlet 
shall be under the disc of the valve. 

315 The feedwater shall discharge at about three-fifths the length 
of a horizontal return tubular boiler from the front head (except a 
horizontal return tubular boiler equipped with an auxiliary feedwater 
heating and circulating device), above the central rows of tubes, when 
the diameter of the boiler exceeds 36 in. The feed pipe shall be car- 
ried through the head or shell near the front end with a brass or steel 
boiler bushing, and securely fastened inside the shell above the tubes. 

316 Feedwater shall not discharge in a boiler close to riveted 
joints in the shell or to furnace sheets. 

317 The feed pipe shall be provided with a check valve near 
the boiler and a valve or cock between the check valve and the boiler, 
and when two or more boilers are fed from a common source, there 
shall also be a globe valve on the branch to each boiler, between the 
check valve and the source of supply. 



78 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

318 When a pump, inspirator or injector is required to supply 
feedwater to a boiler plant of over 50 h. p., more than one such 
appliance shall be provided. 

319 Lamphrey Fronts. Each boiler fitted with a Lamphrey 
boiler furnace mouth protector, or similar appliance, having valves 
on the pipes connecting them to the boiler, shall have these valves 
locked or sealed open. Such valves when used, shall be of the straight- 
way type. 

320 Water Column Pipes. The minimum size of pipes connect- 
ing the water column to a boiler shall be 1 in. Water-glass fittings 
or gage cocks may be connected direct to the boiler. 

3t21 The water connections to the water column of a boiler shall 
be of brass and shall be provided with a cross to facilitate cleaning. 
Either the water column or this connection shall be fitted with a 
drain cock or drain valve with a suitable connection to the ashpit, or 
other safe point of waste. The water column blow-off pipe shall be 
at least % m - 

3(22 The steam connection to the water column of a horizontal 
return tubular boiler shall be taken from the top of the shell or the 
upper part of the head ; the water connection shall be taken from a 
point not less than 6 in. below the center line of the shell. 

Settixg 

3(23 Methods of Support. A horizontal return tubular boiler 
over 78-in. in diameter shall be supported from steel lugs by the out- 
side suspension type of setting, independent of the boiler side walls. 
The lugs shall be so designed that the load is properly distributed 
between the rivets attaching them to the shell and so that not more 
than two of these rivets come in the same longitudinal line on each 
lug. The distance girthwise of the boiler from the centers of the 
bottom rivets to the centers of the top rivets attaching the lugs shall 
be not less than 12 in. The other rivets used shall be spaced evenly 
between these points. If more than four lugs are used they shall be 
set in four pairs. 

3i24 A horizontal return tubular boiler over 54 in., and up to 
and including 78 in. in diameter, shall be supported by the outside 
suspension type of setting, or at four points by not less than eight 
steel or cast-iron brackets set in pairs. A horizontal return tubular 
boiler up to and including 54 in. in diameter shall be supported by 
the outside suspension type of setting, or by not less than two steel 
or cast-iron brackets on each side. 



NEW INSTALLATIONS, PART I, SECTION I, POWER BOILERS 79 

32.5 Lugs or brackets, when used to support boilers, shall be 
properly fitted to the surfaces to which they are attached. The 
shearing stress on the rivets used for attaching the lugs or brackets 
shall not exceed 8 per cent of the strength given in Par. 16. 

326 Wet-bottom stationary boilers shall have a space of not less 
than 1.2 in. between the bottom of the boiler and the floor line, with 
access for inspection. 

3,27 Access and Firing Doors. The minimum size of an access 
door to be placed in a boiler setting shall be Ii2 X 16 in. or equivalent 
area, 11 in. to be the least dimension in any case. 

328 A water tube boiler which is fired by hand shall have firing 
door or doors of the inward opening type unless such doors are pro- 
vided with substantial latching devices to prevent them from being 
blown open by pressure on the furnace side. 

Hydrostatic Tests 

329 Hydrostatic Pressure Tests. After a boiler has been com- 
pleted, it shall be subjected to a hydrostatic test of one and one-half 
times the maximum allowable working pressure. The pressure shall 
be under proper control so that in no case shall the required test 
pressure be exceeded by more than 6 per cent. 

330 During a hydrostatic test, the safety valve or valves shall 
be removed or each valve disc shall be held to its seat by means of a 
testing clamp and not by screwing down the compression screw upon 
the spring. 

Stamping 

3.31 Stamping of Boilers. In laying out shell plates, furnace 
sheets and heads in the boiler shop, care shall be taken to leave at 
least one of the stamps, specified in Par. 36 of these Eules, so located 
as to be plainly visible when the boiler is completed; except that the 
tube sheets of a vertical fire-tube boiler and butt straps shall have at 
least a portion of such stamps visible sufficient for identification when 
the boiler is completed. 

33.2 Each boiler shall conform in every detail to these Eules, and 
shall be distinctly stamped with the symbol as shown in Fig. 19, de- 
noting that the boiler was constructed in accordance therewith. Each 
boiler shall also be stamped by the builder with a serial number and 



so 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



with the builder's name either in full or abbreviated, as indicated in 
Fig. 20. The height of the letters and figures used in stamping shall 
be not less than 14 in. and this stamp shall be placed directly below 
or alongside The American Society of Mechanical Engineers' stamp. 




(Name of State) 

(Number of Boiler) 4 
(Name of Builder) 



STD 



Fig. 19 Official Symbol for Stamp 
to Denote The American So- 
ciety of Mechanical Engi- 
neers Uniform Standard 



Fig. 20 Form of Stamp Proposed 
for the Boiler Manufacturer 



333 Location of Stamps. The location of stamps shall be as 
follows : 

a On horizontal return tubular boilers — on the front head, 
above the central rows of tubes. 

o On horizontal flue boilers — on the front head, above the 
flues. 

c On traction, portable or stationary boilers of the locomo- 
tive type or ,Star water-tube boilers — on the furnace end, 
above the handhole. 

d On vertical fire tube and vertical submerged tube boilers — 
on the shell above the fire door. 

e On water-tube boilers, Babcock & Wilcox, (Stirling, Heine 
and Robb-Mumford standard types — on a head above 
the manhole opening, preferably on the flanging of the 
manhole opening. 

/ On vertical boilers, Climax or Hazleton type — on the top 
head. 

g On Oahall or Wickes vertical water tube boilers — on the 
upper drum, above the manhole opening. 

h On Scotch marine boilers — on the front head, above the 
center or right-nand furnace. 

i On Economic boilers — on the front head, above the central 
row of tubes. 

j For other types and new designs — in a conspicuous loca- 
tion. 

334 The American Society of Mechanical Engineers' standard 
stamp and the boiler builder's stamps shall not be covered by insulat- 
ing or other material. 



PART 1— SECTION II 

BOILERS USED EXCLUSIVELY FOR LOW PRESSURE 

STEAM AND HOT WATER HEATING AND HOT 

WATER SUPPLY 

(this does not apply to economizers or feed water heaters.) 

Boiler Materials 

3,35 The Rules for power boilers shall apply : 

a To all steel plate hot-ivater boilers over 60 in. in diameter. 

b To all steel plate hot-ivater boilers where the grate area ex- 
ceeds 10 sq. ft. and the maximum allowable working pres- 
sure exceeds 50 lb. per sq. in. 

c Under other conditions, the following rules shall apply. 

336 Specifications are given in these Rules, Pars. 23 to 178, for 
the important materials used in the construction of boilers, and where 
given, the materials shall conform thereto. 

337 Flange steel may be used entirely for the construction of 
steam heating boilers covered in this section, but in no case shall 
steel of less than 14 m - m thickness, nor tube sheets or heads of less 
than 5/16 in. in thickness be used. 

Maximum Allowable Working Pressure 

338 The maximum allowable working pressure shall not exceed 
15 lb. per sq. in. on a boiler built under these Rules to be used ex- 
clusively for low pressure steam heating. 

339 A boiler to be used exclusively for low-pressure steam heat- 
ing, may be constructed of cast-iron, or of cast-iron excepting con- 
necting nipples and bolts, or wholly of steel or wrought-iron, or of 
steel and partially cast-iron, or of steel or wrought-iron with cast-iron 
mud rings, door frames and manhole flanges. 

340 All steel plate, hot-water and steam-heating boilers shall have 
a factor of safety of not less than 5. 

81 



82 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E'. 

Boiler Joints 

341 Longitudinal lap joints will be allowed on boilers to be 
used exclusively for low pressure steam heating, when the maximum 
allowable working pressure does not exceed 15 lb. per sq. in., and the 
diameter of the boiler shell does not exceed 60 in. 

342 The longitudinal joints of a horizontal return tubular boiler 
if of the lap type/ shall be not over 12 ft. in length. 

343 In a hot-water boiler to be used excusively for heating build- 
ings or hot water supply when the diameter does not exceed 60 in. and 
the grate area does not exceed 10 sq. ft., longitudinal lap joints will 
be allowed. 

When the grate area exceeds 10 sq. ft. and the diameter of the 
boiler does not exceed 60 in. longitudinal lap joints will be allowed 
providing the maximum allowable working pressure does not exceed 
50 lb. per sq. in. 

344 Protection of Joints. When a boiler is built wholly or 
partially of steel and is used exclusively for low pressure steam heat- 
ing, or when a hot-water boiler is used exclusively for heating build- 
ings or for hot-water supply, it shall not be necessary to water jacket 
the rivets in the fire-box where one end of each rivet is exposed to the 
fire or direct radiant heat from the fire, provided any one of the 
following conditions is fulfilled : 

a Where the ends of the rivets away from the fire are pro- 
tected by means of natural drafts of cold air induced in 
the regular operation of the boiler ; 

b Where the ends of the rivets away from the fire are in the 
open air ; 

c Where the rivets are protected by the usual charges of fresh 
fuel, which is not burned in contact with the rivets. 



W^ashout Holes 

345 A boiler used for hot-water supply shall be provided with 
washout holes for the removal of any sediment that may accumulate 
therein. 

Boiler Openings 

346 Flanged Connections. Openings in boilers having flanged 
connections shall have the flanges conform to the American (Standard 



NEW INSTALLATIONS, PART I, SECTION II, HEATING BOILERS S3 

given in Tables 15 or 16 of the Appendix, for the corresponding pipe 
size, and shall have the corresponding drilling for bolts or studs. 

Safety Valves 

317 Outlet Connections for Safety and Water Belief Valves. 
Every boiler shall have proper outlet connections for the required 
safety, or water relief valve or valves, independent of any other con- 
nection outside of the boiler or any internal pipe in the boiler, the 
area of the opening to be at least equal to the aggregate area of all of 
the safety valves with which it connects. A screwed connection may 
be used for attaching a safety valve to a heating boiler. This rule 
applies to all sizes of safety valves. 

31:8 Safety Valves. Each steam boiler shall be provided with 
one or more safety valves of the spring-pop type which cannot be 
adjusted to a higher pressure than 15 lb. per sq. in. 

349 Water Relief Valves. Each liot-water boiler shall be pro- 
vided with one or more water relief valves with open discharges hav- 
ing outlets in plain sight. 

350 A hot-ivater boiler built for a maximum allowable working 
pressure of 30 lb. per sq. in. and used exclusively for heating build- 
ings, or for hot-water supply, shall be provided with a water relief 
valve or valves, which cannot be adjusted for a pressure in excess 
of 30 lb. per sq. in. 

351 No safety or water relief valve shall be smaller than 1 in. 
nor greater than 4% in. nominal size. 

35.2' When two or more safety or water relief valves are used 
on a boiler they may be single or twin valves. 

353 Safety or water relief valves shall be connected to boilers 
independent of other connections and be attached directly or as 
close as possible to the boiler, without any intervening pipe or fittings, 
except the Y-base forming a part of the twin valve or the shortest 
possible connection. A safety or water relief valve shall not be con- 
nected to an internal pipe in the boiler. <Safety valves shall be con- 
nected so as to stand upright, with the spindle vertical, when possible. 

354 No shut-off of any description shall be placed between the 
safety or water relief valves and boilers, nor on discharge pipes be- 
tween them and the atmosphere. 

355 When a discharge pipe is used its area shall be not less than 
the area of the valve or aggregate area of the valves with which it 



84 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



connects, and the discharge pipe shall be fitted with an open drain 
to prevent water from lodging in the upper part of the valve or in 
the pipe. When an elbow is placed on a safety or water relief valve 
discharge pipe, it shall be located close to the valve outlet or the pipe 
shall be securely anchored and supported. The safety or water relief 
valves shall be so located and piped that there will be no danger of 
scalding attendants. 

356 Each safety valve used on a steam heating boiler shall have 
a substantial lifting device which shall be so connected to the disc 
that the latter can be lifted from its seat a distance of not less than 



TABLE 9 


ALLOWABLE SIZES OF SAFETY VALVES FOR HEATING BOILERS 


Water Evaporated 














per Sq. Ft. of 
Grate Surface per 


75 


100 


160 


160 


200 


240 


Hr., Lb. 














Maximum allowable 


Zero 


Over 25 


Over 50 


Over 100 


Over 150 


Over 200 
Lb. 


Working Pressure, 


to 


to 


to 


to 


to 


Lb. per Sq. In. 


25 Lb. 


50 Lb. 


100 Lb. 


150 Lb. 


200 Lb. 


Diameter 


Area 














of Valve, 


of Valve, 






Area of Gr 


ate, Sq. Ft. 






In. 


Sq. In. 














1 


0.7854 


2.00 


2.50 


2.75 


3.25 


3.5 


3.75 


1M 


1.2272 


3.25 


4.00 


4.25 


5.00 


5.5 


5.75 


V4 


1 . 7671 


4.50 


5.50 


6.00 


7.25 


8.0 


8.50 


2 


3.1416 


8.00 


9.75 


10.75 


13.00 


14.0 


15.00 


2^ 


4.9087 


12.50 


15.00 


16.50 


20.00 


22.0 


23.00 


3 


7.0686 


17.75 


21 . 50 


24.00 


29.00 


31.5 


33.25 


sy 2 


9.6211 


24.00 


29.50 


32.50 


39.50 


43.0 


45.25 


4 


12.5660 


31.50 


38.25 


42.50 


51.50 


56.0 


59.00 


AV 2 


15.9040 


40.00 


48.50 


53.50 


65.00 


71.0 


74.25 



one-tenth of the nominal diameter of the seat when there is no pres- 
sure on the boiler. A relief valve used on a hot-water heating boiler 
need not have a lifting device. 

357 Every safety valve or water relief valve shall have plainly 
stamped on the body or cast thereon the manufacturer's name or 
trade mark and the pressure at which it is set to blow. The seats and 
discs of safety or water relief valves shall be made of non-ferrous 
material. 

358 The minimum size of safety or water relief valve or valves 
for each boiler shall be governed by the grate area of the boiler, as 
shown by Table 9. 



NEW INSTALLATIONS, PART I, SECTION II, HEATING BOILERS 85 

When the conditions exceed those on which Table 9 is based, the 
following formula for bevel and flat seated valves shall be used : 

in which 

A = area of direct spring-loaded safety valve per square foot 
of grate surface, sq. in. 

W = weight of water evaporated per square foot of grate sur- 
face per second, lb. 

P = pressure (absolute) at which the safety valve is set to 
blow, lb. per sq. in. 

359 Double Grate Down Draft Boilers. In determining the 
number and size of safety valves or water relief valves the grate area 
shall equal the area of the upper grate plus one-half of the area of 
the lower grate. 

360 Boilers Fired With Oil or Gas. In determining the number 
and size of safety or water relief valve or valves for a boiler using gas 
or liquid fuel, 15 sq. ft. of heating surface shall be equivalent to one 
square foot of grate area. If the size of grate for use of coal is evi- 
dent from the boiler design, such size may be the basis for the de- 
termination of the safety valve capacity. 

iSteam and Water Gages 

361 Steam Gages. Each steam boiler shall have a steam gage 
connected to the steam space or to the water column or its steam 
connection. The steam gage shall be connected to a syphon or 
equivalent device of sufficient capacity to keep the gage tube filled 
with water and so arranged that the gage cannot be shut off from the 
boiler except by a cock placed near the gage and provided with a tee 
or lever handle arranged to be parallel to the pipe in which it is lo- 
cated when the cock is open. Connections to gages shall be of brass, 
copper or bronze composition. The dial of a steam gage for a steam 
heating boiler shall be graduated to not less than 30 lb. 

36(2 Pressure or Altitude Gages. Each liot-ivater boiler shall 
have a gage connected in such a manner that it cannot be shut off 
from the boiler except by a cock with tee or lever handle, placed on the 
pipe near the gage. The handle of the cock shall be parallel to the pipe 
in which it is located when the cock is open. Connections to gages 
shall be made of brass, copper or bronze composition. The dial of 



86 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

the pressure or altitude gage shall be graduated to not less than iy 2 
times the maximum allowable working pressure. 

363 Thermometers. Each hot-water boiler shall have a ther- 
mometer so located and connected that it shall be easily readable when 
observing the water pressure or altitude. The thermometer shall be 
so located that it shall at all times indicate the temperature in deg. 
fahr., of the water in the boiler. 

Fittings and Appliances 

364 Bottom Blow-off Pipes. Each boiler shall have a blow-off 
pipe, fitted with a valve or cock, in direct connection with the lowest 
water space practicable. 

365 Damper Regulators. When a pressure damper regulator is 
used, the boiler pressure pipe shall be connected to the steam space of 
the boiler. 

366 Water Glasses. Each steam boiler shall have one or more 
water glasses. 

367 Gage Cocks. Each steam boiler shall have two or more gage 
cocks located within the range of the visible length of the water glass. 

• 3i68 Water Column Pipes. The minimum size of pipes connect- 
ing the water column of a boiler shall be 1 in. Water-glass fittings 
or gage cocks may be connected direct to the boiler. The steam con- 
nection to the water column of a horizontal return tubular boiler 
shall be taken from the top of shell or the upper part of the head ; the 
water connection shall be taken from a point not less than 6 in. below 
the center line of the shell. No connections, except for damper regu- 
lator, drains or steam gages, shall be placed on the pipes connecting 
a water column to a boiler. 

Methods of Setting 

369 1 Wet-bottom steel plate boilers shall have a space of not less 
than 12 in. between the bottom of the boiler and the floor line with 
access for inspection. 

370 Access Doors. The minimum size of access door used in 
boiler settings shall be 12 X 16 in. or equivalent area, the least 
dimension being 11 in. 

371 The longitudinal joints of a horizontal return tubular 
boiler shall be located above the fire-line. 



new installations, part i, section ii, heating boilers 87 
Hydrostatic Tests 

372 A shop test of 60 lb. per sq. in. hydrostatic pressure shall be 
applied to steel or cast-iron boilers or to the sections of cast-iron 
boilers which are used exclusively for low pressure steam heating. 

373 Hot-water boilers for a maximum allowable working pressure 
not exceeding 30 lb. per sq. in. used exclusively for heating buildings 
or for hot-water supply, when constructed of cast-iron, or of cast-iron 
excepting the connecting nipples and bolts, shall be subjected to a 
shop test of 60 lb. per sq. in. hydrostatic pressure applied to the boiler 
or the sections thereof. 

374 A maximum allowable working pressure in excess of 30 lb. 
per sq. in. will be allowed on a hot-water boiler constructed of cast- 
iron, or of cast-iron excepting the connecting nipples and bolts, used 
exclusively for heating buildings or for hot-water supply, provided 
such boilers or their sections have been subjected to a shop hydrostatic 
test of two and one-half times the actual working pressure. 

375 Individual shop inspection shall be required only for boilers 
which come under the rules for power boilers. 

(Stamping 

376 Each plate of a completed boiler shall show a sufficient 
portion of the plate maker's stamp for identification. 

377 Name. All boilers referred to in this section shall be plainly 
and permanently marked with the manufacturer's name and the maxi- 
mum allowable working pressure. 



PART II EXISTING INSTALLATIONS 

Maximum Allowable Working Pressure 
378 The maximum allowable working pressure on the shell of a 
boiler or drum shall be determined by the strength of the weakest 
course, computed from the thickness of the plate, the tensile strength 
of the plate, the efficiency of the longitudinal joint, the inside diame- 
ter of the course and the factor of safety allowed by these Rules. 

TS X t X E 

— 7? v rro '= maximum allowable working pressure, lb. per sq. in. 

where 

TS = ultimate tensile strength of shell plates, lb. per sq. in. 
t = thickness of shell plate, in weakest course, in. 
E = efficiency of longitudinal joint, method of determining 

which is given in Par. 181, of these Rules 
R = inside radius of the weakest course of the shell or drum, 
in. 
FS = factor of safety allowed by these Rules 
*379 Boilers of Butt and Double strap construction, in ser- 
vice for a period of one year after these Orders become effective, 
shall be operated with a factor of safety of at least four (4) by 
the formula, Par. 378. Five years after these Orders become 
effective, the factor of safety shall be at least four and five-tenths 
(4.5). In no case shall the maximum allowable working pressure 
on old boilers be increased, unless they are being operated at a 
lesser pressure than would be allowable for new boilers, in which 
case the changed pressure shall not exceed that allowable for new 
boilers of the same construction. 

*380 (a) The lowest factor of safety used for boilers, the shells 
or drums of which are exposed to the direct products of combustion, 
and the longitudinal joints of which are of lap riveted construction, 
shall be as follows : 

4i for boilers not over five (5) years old. 

4£ for boilers over five (5) and not over ten (10) years old. 

4f for boilers over ten (10) and not over fifteen (15) years old. 

5 for boilers over fifteen (15) and not over twenty (20) years old. 

For each five (5) years thereafter the factor of safety shall be 

increased by a further one-half (-J) point, unless conditions are 

such as to warrant a continuance of a factor of safety of five (5), 

and provided further that within one (1) year after the date these 

Orders go into effect, a factor of safety of four (4) may be used on 

boilers not over ten (10) years old, where conditions warrant. 

(b) The lowest factor of safety for boilers, the shells or drums of 

which are NOT exposed to the direct products of combustion, and 

♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

the longitudinal joints of which are of lap riveted construction, 
shall be as follows : 

4 for boilers not over ten (10) years old. 

4£ for boilers over ten (10) and not over fifteen (15) years old. 

41 for boilers over fifteen (15) and not over twenty (20) years old. 

5 for boilers over twenty (20) years old. 

For each five years thereafter, the factor of safety shall be in- 
creased by a further one-half (-J) point, unless conditions are such 
as to warrant a continuance of a factor of safety of five (5), and 
provided further that within one (1) year after the date these 
Orders go into effect, a factor of safety of four (4) may be used 
on boilers not over ten (10) years old where conditions warrant. 

*381 Second-hand stationary boilers, by which are meant 
boilers where both the ownership and location are changed, shall 
have a factor of safety of at least 5J, by the formula Par. 378, one 
year after these Rules become effective, unless constructed in ac- 
cordance with the Rules contained in Part I, when the factor shall 
be at least 5. 

*382 Cast-Iron Headers and Mud Drums. All watertube 
boilers having cast iron or malleable iron headers or mud drums or 
junction boxes shall where conditions warrant be permitted to 
carry pressures up to 200 lb. per square inch provided that all such 
headers, mud drums and junction boxes shall be replaced by forged 
steel or steel castings within five (5) years after the date these 
Orders go into effect or else the pressure shall be so reduced as not 
to exceed 160 lb. per square inch. 

*383 Steam Heating Boilers. The maximum allowable working 
pressure shall not exceed 15 lb. per sq. in. on a boiler designed ex- 
clusively for low pressure steam heating. 

384 No pressure shall be allowed on a boiler on which a crack 
is discovered along the longitudinal riveted joint. 

Strength of Materials 
*385 Tensile Strength. When the tensile strength of steel or 
wrought iron shell plates is not known, it shall be taken as 55,000 
lb. per square inch for steel, and 45,000 lb. per square inch for 
wrought iron. When the tensile strength of cast iron is not known, 
it shall be taken as 18,000 lb. per square inch. 

386 Strength of Rivets in Shear. In computing the ultimate 
strength of rivets in shear, the following values in pounds per square 
inch of the cross-sectional area of the rivet shank shall be used : 

Iron rivets in single shear 38,000 

Iron rivets in double shear 1 76,000 

Steel rivets in single shear 44,000 

Steel rivets in double shear 88,000 

The cross-sectional area shall be that of the rivet shank after 
driving. 

387 Crushing Strength of Mild Steel. The resistance to crush- 
ing of mild steel shall be taken at 95,000 lb. per sq. in. of cross- 
sectional area. 

♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



EXISTING INSTALLATIONS, PART II 



91 



TABLE 10 SIZES OF RIVETS BASED ON PLATE THICKNESS 



Tnicknesa of plate 

Diameter of rivet after driving 

Thickness of plate 

Tiameter of rivet after driving 









3/T" 



w 



if* 

if* 






*388 Rivets. When the diameter of the rivet holes in the 
longitudinal joints of a boiler is not known, the diameter and cross- 
sectional area of rivets after driving may be ascertained from 
Table 10 for boilers bnilt in an Eastern shop, or by cutting out one 
rivet in the body of the joint. 

For boilers built on the Pacific Coast, the rivets are to be assumed 
as three-fourths (%) of an inch before driving and thirteen- 
sixteenths ( 13 /iq) of an inch after driving in five-sixteenths (%e) 
inch and eleven-thirty-seconds C 1 ^) i ncn plate. 

Safety Valves for Power Boilers 

389 The safety valve capacity of each boiler shall be such that 
the safety valve or valves will discharge all the steam that can be 
generated by the boiler without allowing the pressure to rise more 
than 6 per cent above the maximum allowable working pressure, or 
more than 6 per cent above the highest pressure to which any valve 
is set. 

390 One or more safety valves on every boiler shall be set at or 
below the maximum allowable working pressure. The remaining 
valves may be set within a range of 3 per cent above the maximum 
allowable working pressure, but the range of setting of all of the 
valves on a boiler shall not exceed 10 per cent of the highest pressure 
to which any valve is set. 

391 Safety valve capacity may be checked in any one of three 
different ways, and if found sufficient, additional capacity need not 
be provided : 

a By making an accumulation test, by shutting off all other 
steam discharge outlets from the boiler and forcing the 
fires to the maximum. The safety valve equipment shall 
be sufficient to prevent an excess pressure beyond 6 per 
cent as specified in Par. 389. 

o By measuring the maximum amount of fuel that can be 
burned and computing the corresponding evaporative 

♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



92 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

capacity upon the basis of the heating value of the fuel. 
See Appendix, Pars. 421 to 427. 
c By determining the maximum evaporative capacity by 
measuring the feed water. The sum of the safety valve 
capacities shall be equal to or greater than the maximum 
evaporative capacity of the boiler. 

392 In case either of the methods outlined in sections b or c of 
Par. 391 is employed, the safety valve capacities shall be taken at the 
maximum values given in Table 8 for spring loaded pop safety 
valves, or 0.66 times the maximum values given in Table 8, for lever 
safety valves. 

393 When additional valve capacity is required, any valves 
added shall conform to the requirements in Part I of these Rules. 

*394 No valve of any description shall be placed between the 
safety valve and the boiler, nor on the discharge pipe between the 
safety valve and the atmosphere. When a discharge pipe is used, it 
shall be not less than the full size of the valve, and the discharge 
pipe shall be fitted with an open drain to prevent water lodging in 
the upper part of the safety valve or in the pipe. If a muffler is used 
on a safety valve it shall have sufficient outlet area to prevent back 
pressure from interfering with the proper operation and discharge 
capacity of the valve. The muffler plates or other devices shall be so 
constructed as to avoid any possibility of restriction of the steam 
passages due to deposit. When an elbow is placed on a safety valve 
discharge pipe, it shall be located close to the safety valve outlet or 
the pipe shall be properly secured. All safety valve discharges 
shall be so located or piped as to be carried clear from running 
boards or working platforms used in controlling the main stop 
valves of boilers or steam headers. 

Where safety valve discharge pipes run through walls, proper 
clearances shall be allowed. 

Fittings and Appliances 

395 Water Glasses and Gage Cocks. Each steam boiler shall 
have at least one water glass, the lowest visible part of which shall 
be not less than 2 in. above the lowest permissible water level. 

396 Each boiler shall have three or more gage cocks, located 
within the range of the visible length of the water glass, when the 
maximum allowable working pressure exceeds 15 lb. per sq. in., 
except when such boiler has two water glasses with independent con- 
nections to the boiler, located on the same horizontal line and not less 
than two (2) feet apart. 



♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



EXISTING INSTALLATIONS, PART II 



93 



*396a Exception should be made where the height of the seg- 
ment above the tubes on the boiler does not exceed twelve (12) 
inches; in which case, at least two (2) gage cocks located within the 
visible range of the water glass must be used. 

*397 No connections except for damper regulator, oil burner 
regulator, feed water regulator, drains, or steam gages, shall be 
placed on the pipes connecting a water column to a power boiler. 

# 398 Steam Gages. Each steam boiler shall have a steam gage 
connected to the steam space or to the water column or to its steam 
connection. The steam gage shall be connected to a syphon or 
equivalent device of sufficient capacity to keep the gage tube filled 
with water and so arranged that the gage cannot be shut off from the 
boiler except by a cock placed near the gage and provided with a tee 
or lever handle arranged to be parallel to the pipe in which it is 
located when the cock is open. 

*398a Each boiler shall be provided with a one-quarter (£) 
inch pipe size valved connection for attaching a test gage when the 
boiler is in service, so that the accuracy of the boiler steam gage 
can be ascertained. 

399 Stop Valves. 1 Each steam outlet from a power boiler 
(except safety valve connections) shall be fitted with a stop valve 
located as close as practicable to the boiler. 

400 When a stop valve is so located that water can accumulate, 
ample drains shall be provided. 

401 Bottom Blow-Off Pipes. Each boiler shall have a blow-off 
pipe fitted with a valve or cock, in direct connection with the lowest 
water space practicable. 

402 When the maximum allowable working pressure exceeds 
125 lb. per sq. in., the blow-off pipe shall be extra heavy from boiler 
to valve or valves, and shall run full size without reducers or bush- 
ings. All fittings between the boiler and valve shall be steel, extra 
heavy malleable iron or extra heavy cast-iron. 

403 When the maximum allowable working pressure exceeds 
125 lb. per sq. in., each bottom blow-off pipe shall be fitted with an 
extra heavy valve or cock. Preferably two (2) valves, or a valve 
and a cock should be used on each blow-off, in which case, such 
valves, or valve and cock, shall be extra heavy. 

# 404 The blow-off pipe or boiler rest, or both, when exposed to 
direct action of products of combustion, shall be properly protected 

3 It is recommended that when two or more boilers are connected to a common 
steam main, two stop valves, with an ample free blow drain between them, be 
placed in the steam connection between each boiler and the steam main. Also 
that the discharge of this drain valve be visible to the operator while manipulat- 
ing the valve and further that the stop valves consist preferably of one auto- 
matic non-return valve (set next the boiler) and a second valve of the outside 
screw and yoke type ; or two valves of the outside screw and yoke type may be 
used. 

♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



94 REPORT OP BOILER CODE COMMITTEE, AM.SOC.M.E. 

by a sleeve, asbestos rope, or other suitable material, or a protecting 
pier of brick built in " V" shape, or other pier with corner pointing 
toward and against path of flame. 

405 An opening in the boiler setting for a blow-off pipe shall be 
arranged to provide for free expansion and contraction. 

406 Feed Piping. 1 The feed pipe of a steam boiler operated at 
more than 15 lb. per sq. in. maximum allowable working pressure, 
shall be provided with a check valve near the boiler and a valve or 
cock between the check valve and the boiler, and when two or more 
boilers are fed from a common source, there shall also be a globe 
valve on the branch to each boiler, between the check valve and the 
source of supply. When a globe valve is used on a feed pipe, the 
inlet shall be under the disc of the valve. 

*406a The main feed in boilers operated at more than fifteen 
(15) pounds per square inch maximum allowable working pressure 
shall not enter the boiler through the blow-off, unless clearly im- 
practicable to introduce it elsewhere. 

*4066 When a pump, inspirator, or injector is required to sup- 
ply feed water to a boiler of over 50 hp., more than one such 
mechanical appliance shall be provided. 

407 Lamphrey Fronts. Each boiler fitted with a Lamphrey 
boiler furnace mouth protector, or similar appliance, having valves 
on the pipes connecting them to the boiler, shall have these valves 
locked or sealed open. Such valves, when used, shall be of the 
straightway type. 

Hydrostatic Pressure Tests. 
*408 Test Pressure. When a hydrostatic test is applied the 
required test pressure shall be not more than one and one-half (1-J) 
times the maximum allowable working pressure, and not less than 
the maximum allowable working pressure. The pressure shall be 
under proper control so that in no case shall the required test 
pressure be exceeded by more than two (2) per cent. 

409 During a hydrostatic test of a boiler, the safety valve or 
valves shall be removed or each valve disc shall be held to its seat by 
means of a testing clamp and not by screwing down the compression 
screw upon the spring. 

x It is recommended that wherever possible the feed water entering boilers shall 
be not less than one hundred twenty (120) degrees Fahrenheit. 

♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



APPENDIX 



Efficiency of Joints 

410 Efficiency of Riveted Joints. The ratio which the strength 
ot a unit length of a riveted joint has to the same unit length of 
the solid plate is known as the efficiency of the joint and shall be 
calculated by the general method illustrated in the following examples : 
TS = tensile strength stamped on plate, lb. per sq. in. 
t = thickness of plate, in. 
o = thickness of butt strap, in. 

P = pitch of rivets, in., on row having greatest pitch 
d = diameter of rivet after driving, in. == diameter of rivet 
hole 




£ 



f>x_ 




<f> <$> © © © 



Fig. 21 Example of Lap Joint, Longitudinal 
or Circumferential, Single-Eiveted 



a = cross-sectional area of rivet after driving, sq. in. 

s = shearing strength of rivet in single shear, lb. per sq. in., 

as given in Par. 16 
S = shearing strength of rivet in double shear, lb. per sq. in., 

as given in Par. 16 
c = crushing strength of mild steel, lb. per sq. in., as given 

in Par. 15 
n = number of rivets in single shear in a unit length of joint 
N = number of rivets in double shear in a unit length of joint. 

95 



96 



REPORT OP BOILER CODE COMMITTEE, AM.SOC.M.E. 



411 Example: Lap joint, longitudinal or circumferential, single- 
riveted. 

A = strength of solid plate = PXtXTS 

B = strength of plate beween rivet holes = (P — d)t X TS 

C = shearing strength of one rivet in single shear —nXsXa 

D = crushing strength of plate in front of one rivet = dXtXc 

Divide B, C or D (whichever is the least) by A, and the quotient will be the 

efficiency of a single-riveted lap joint as shown in Fig. 21. 



T£ = 55,000 lb. persq. in. 
* = Min.=0.25in. 
P = 1 5 A in. = 1.625 in. 
d = H in. =0.6875 in. 
a =0.3712 sq. in. 
s = 44,000 lb. per sq. in. 

r 



c = 95,000 lb. per sq. in. 
A = 1.625X0.25X55,000=22,343 
B = (1.625—0.6875) 0.25X55,000 = 12,890 
C = 1 X44,000 X0.3712 = 16,332 
D =0.6875 X0.25 X95,000 = 16,328 




22 Example of Lap Joint, Longitudinal 
or Circumferential, Double-Eiveted 



12,890 (P) 



- =0.576= efficiency of joint 



22,343 (A) 

41,2 Example: Lap joint, longitudinal or circumferential, double- 
riveted. 

A = strength of solid plate = PXtXTS 
B = strength of plate between rivet holes = (P — d) t X TS 
C = shearing strength of two rivets in single shear =n Xs Xa 
D = crushing strength of plate in front of two rivets =nXdXtXc 
Divide B, C or D (whichever is the least) by A, and the quotient will be the 
efficiency of a double-riveted lap joint, as shown in Fig. 22. 

c =95,000 lb. per sq. in. 
^=2.875X0.3125X55,000 = 49,414 
£ = (2.875—0.75)0.3125X55,000=36,523 
C =2X44,000X0.4418 =38,878 
D =2 X0.75X0.3125 X95,000 =44,531 



T£ = 55,000 lb. persq. in. 
t = & in. =0.3125 in. 
P =2% in. =2.875 in. 
d = % in. =0.75 in. 
a =0.4418 sq. in. 
s = 44,000 lb. per sq. in. 



36,523 (B) 
49,414 (A) 



= 0.739 = efficiency of joint 



APPENDIX 97 

413 Example: Butt and double strap joint, double-riveted. 

A = strength of solid plate = PXtXTS 

B = strength of plate between rivet holes in the outer row = (P — d) t X TS 

C = shearing strength of two rivets in double shear, plus the shearing strength of 
one rivet in single shear =NXSXa+nXsXa 

D— strength of plate between rivet holes in the second row, plus the shearing 
strength of one rivet in single shear in the outer row = (P — 2d) t X TS 
+nXsXa 




Fig. 23 Example of Butt and Double Strap 
Joint, Double-Eiveted 



E = strength of plate between rivet holes in the second row, plus the crushing 
strength of butt strap in front of one rivet in the outer row = (P — 2d) t 
XTS+dXbXc 

F = crushing strength of plate in front of two rivets, plus the crushing strength 
of butt strap in front of one rivet = N XdXtXc+nXdXbXc 

G = crushing strength of plate in front of two rivets, plus the shearing strength 
of one rivet in single shear =iV"XdX^Xc+nXsXa 

H= strength of butt straps between rivet holes in the inner row = (P — 2d) 2b 
X TS. This method of failure is not possible for thicknesses of butt straps 
required by these Rules and the computation need only be made for old 
boilers in which thin butt straps have been used. For this reason this 
method of failure will not be considered in other joints. 

Divide B, C, D, E } F, G-or H (whichever is the least) by A, and the quotient will 



98 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



be the efficiency of a butt and double strap joint, double-riveted, as shown in 
Fig. 23. 

TS = 55,000 lb. per sq. in. a = 0.6013 sq. in. 

t = % in. =0.375 in. s =44,000 lb. per sq. in. 



6= A in. =0.3125 in. 
P=4%in. =4.875 in. 
d= Kin. =0.875 in. 



£ = 88,000 lb. persq. in. 
c =95,000 lb. per sq. in. 



Number of rivets in single shear in a unit length of joint = 1. 
Number of rivets in double shear in a unit length of joint =2. 




Tig. 24 Example of Butt and Double Strap Joint, Triple-Kiveted 



A =4.875 X0.375 X55,000 = 100,547 

#=(4.875—0.875)0.375X55,000 = 82,500 

C =2X88,000X0.6013 + 1X44,000X0.6013 = 132,286 

D = (4.875—2 X0.875) 0.375 X 55,000+1 X44,000X0.6013 =90,910 

E = (4.875— 2X0.875) 0.375X55,000+0.875X0.3125X95,000 =90,429 

F =2X0.875X0.375X95,000 +0.875X0.3125X95,000 = 88,320 

(7=2X0.875X0.375X95,000+1X44,000X0.6013 = 88,800 

82,500 (B) 



100,547 (A) 



= 0.820 = efficiency of joint 



414 Example: Butt and double strap joint, triple-riveted. 
A = strength of solid plate = PXtXTS 

B = strength of plate between rivet holes in the outer row = (P—d) tXTS 
C = shearing strength of four rivets in double shear, plus the shearing strength 

of one rivet in single shear =iV X S Xa+nXsX a 
D = strength of plate between rivet holes in the second row, plus the shearing 

strength of one rivet in single shear in the outer row = (P — 2d) t X TS 

-\-nXsXa 



APPENDIX 99 

E = strength of plate between rivet holes in the second row, plus the crushing 
strength of butt strap in front of one rivet in the outer row = (P — 2d) t 
XTS+dXbXc 

F = crushing strength of plate in front of four rivets, plus the crushing strength 
of butt strap in front of one rivet = NXdXtXc+nXdXbXc 

G = crushing strength of plate in front of four rivets, plus the shearing strength 
of one rivet in single shear = NXdXtXc-\-nXsXa 

Divide B, C, D, E, F or G (whichever is the least) by A, and the quotient will 
be the efficiency of a butt and double strap joint, triple-riveted, as shown in Fig. 24. 

TS = 55,000 lb. per sq. in. a =0.5185 sq. in. 

t= % in. =0.375 in. s =44,000 lb. per sq. in. 

b = & in. =0.3125 in. S =88,000 lb. per sq. in. 

P = 63^in.=6.5in. c= 95,000 lb. per sq. in. 
d= H in. =0.8125 in. 

Number of rivets in single shear in a unit length of joint = 1. 
Number of rivets in double shear in a unit length of joint =4. 

A =6.5X0.375X55,000 = 134,062 

B = (6.5—0.8125) 0.375X55,000 = 117,304 

C =4X88,000X0.5185 + 1X44,000X0.5185 =205,326 

D = (6.5— 2X0.8125)0.375X55,000 + 1X44,000X0.5185 = 123,360 

E = (6.5—2 X0.8125) 0.375 X55,000 +0.8125 X0.3125 X95,000 = 124,667 

F =4X0.8125X0.375X95,000+1X0.8125X0.3125X95,000 = 139,902 

G =4 X0.8125 X0.375 X95,000+l X44,000 X0.5185 = 138,595 

117,304(5) 

-—=0.875 = efficiency of joint 

134,062(4) J 

415 Example: Butt and double strap joint, quadruple-riveted. 

A = strength of solid plate = PXtXTS 

B = strength of plate between rivet holes in the outer row = (P — d) t X TS 

C = shearing strength of eight rivets in double shear, plus the shearing strength 
of three rivets in single shear=2VX$Xa+nXsXa 

D = strength of plate between rivet holes in the second row, plus the shearing 
strength of one rivet in single shear in the outer row = (P — 2d) tXTS 
+lXsXa 

E= strength of plate between rivet holes in the third row, plus the shearing 
strength of two rivets in the second row in single shear and one rivet in 
single shear in the outer row = (P — 4d) t X TS+nXs Xa 

F~ strength of plate between rivet holes in the second row, plus the crushing 
strength of butt strap in front of one rivet in the outer row = (P — 2d) t 
XTS+dXbXc 



100 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



G = strength of plate between rivet holes in the third row, plus the 

strength of butt strap in front of two rivets in the second row 

rivet in the outer row = (P— 4d) tXTS+nXdXbXc 
H = crushing strength of plate in front of eight rivets, plus the crushing strength 

of butt strap in front of three rivets = NXdXtXc+nXdX b Xc 
7 = crushing strength of plate in front of eight rivets, plus the shearing 

of two rivets in the second row and one rivet in the outer row, 

shear = NXdXtXc+nXsXa 
Divide B, C, D, E, F, G, H or I (whichever is the least) by A, and the 
will be the efficiency of a butt and double strap joint quadruple-riveted, 
in Fig. 25. 



crushing 
and one 



strength 
in single 

quotient 
as shown 




Fig. 25 Example of Butt and Double Strap Joint, Quadruple -Kiveted 



a =0.6903 sq. in. 
s=44,000 lb. per sq. in. 
S = 88,000 lb. persq. in. 
c =95,000 lb. persq. in. 



T£ = 55,000 1b. persq. in. 

t= Yl in. =0.5 in. 

6= ■& in. =0.4375 in. 
P = 15in. 

d= if in. =0.9375 in. 
Number of rivets in single shear in a unit length of joint =3. 
Number of rivets in double shear in a unit length of joint = 8. 
A = 15 X 0.5 X 55,000 = 412,500 
£ = (15—0.9375) 0.5X55,000 = 386,718 
C = 8X88,000X0.6903+3X44,000X0.6903 =577,090 
D = (15—2 X0.9375) 0.5X55,000+1 X 44,000X0. 6903 =391,310 
E = (15—4 X0.9375) 0.5 X55,000+3 X44,000 X0.6903 = 400,494 
F = (15—2 X0.9375) 0.5 X 55,000 +0.9375 X 0.4375 X 95,000 =399,902 
G = (15 — 4 X0.9375) 0.5 X55,000+3 X0.9375 X0.4375 X95,000 = 426,269 
# = 8X0.9375X0.5X95,000+3X0.9375X0.4375X95,000=473,145 

7 = 8 X0.9375 X0.5 X95,000 +3 X44,000 X0.6903 = 447,369 



386,718 (B) 
412,500 (A) 



=0.937 = efficiency of joint 



APPENDIX 



101 



416 Example: Butt and double strap joint, quintuple-riveted. 

A = strength of solid plate = PXtXTS 

B= strength of plate between rivet holes in the outer row = (P — d) tXTS 

C= shearing strength of 16 rivets in double shear, plus the shearing strength of 

seven rivets in single shear =NXSXa-\-nXsXa 
D = strength of plate between rivet holes in the second row, plus the shearing 

strength of one rivet in single shear in the outer row = (P — 2d) tXTS 

+lXsXa 
E = strength of plate between rivet holes in the third row, plus the shearing 

strength of two rivets in the second row in single shear and one rivet in 

single shear in the outer row = (P — Ad) t X TS-\-S XsXa 




Fig. 26 Example of Butt and Double Strap Joint, Quintuple-Biveted 



F = strength of plate between rivet holes in the fourth row, plus the shearing 
strength of four rivets in the third row, two rivets in the second row and 
one rivet in the outer row in single shear = (P — Sd) tXTS+nXsXa 

G = strength of plate between rivet holes in the second row, plus the crushing 
strength of butt strap in front of one rivet in the outer row = (P — 2d) t 
XTS+dXbXc 

H = strength of plate between rivet holes in the third row, plus the crushing 
strength of butt strap in front of two rivets in the second row and one 
rivet in the outer row = (P— Ad) tXTS+SXdXbXc 

1 = strength of plate between rivet holes in the fourth row, plus the crushing 
strength of butt strap in front of four rivets in the third row, two rivets 
in the second row and one rivet in the outer row = (P — Sd) tXTS-\-n 
XdXbXc 



102 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



J = crushing strength of plate in front of 16 rivets, plus the crushing strength of 

butt strap in front of seven rivets = N XdXtXc-\-nXdX b Xc 
K = crushing strength of plate in front of 16 rivets, plus the shearing strength 
of four rivets in the third row, two rivets in the second row and one rivet 
in the outer row in single shear = NXdXt Xc-\-nXsXa 
Divide B, C, D, E, F, G, H, 1, J or K (whichever is the least) by A, and the quo- 
tient will be the efficiency of a butt and double strap joint, quintuple-riveted, as 
shown in Fig. 26 or Fig. 27. 

in. a = 1.3529 sq. in. 

s =44,000 lb. per sq. in. 
£ = 88,000 lb. persq. in. 
c = 95,000 lb. per sq. in. 



T£ = 55,000 lb. persq. 
t= % in. =0.75 in. 
b= Y% in. =0.5 in. 
P=36in. 



d = \h in. = 1.3125 in. 




Fig. 27 Example of Butt and Double Strap Joint, Quintuple-Eiveted 



Number of rivets in single shear in a unit length of joint = 7. 
Number of rivets in double shear in a unit length of joint = 16. 

A =36 X0.75 X55,000 = 1,485,000 
B = (36— 1 .3 125) 0.75 X 55,000 = 1,430,860 
C = 16 X88,000 X 1.3529 +7 X44,000 X 1.3529 =2,321,576 
D = (36—2 X 1 .3 125) 0.75 X 55,000 + 1 X44,000 X 1 .3529 = 1,436,246 
E = (36—4 X 1 .3 125) 0.75 X 55,000 +3 X44,000 X 1 .3529 = 1,447,020 
F = (36—8 X 1 .3125) 0.75 X 55,000+7 X44,000 X 1 .3529 = 1,468,568 
G = (36— 2X1.3125)0.75X55,000 + 1.3125X0.5X95,000 = 1,439,064 
H = (36—4 X 1 .3125) 0.75 X 55,000 +3 X 1 .3125 X0.5 X95,000 = 1,455,472 
/ = (36—8 X 1 .3125) 0.75 X 55,000+7 X 1 .3125 X0.5 X95,000 = 1,488,141 
J = 16X1.3125X0.75X95,000+7X1.3125X0.5X95,000 = 1,932,266 
K = 16X1.3125X0.75X95,000+7X44,000X1.3529 = 1,912,943 



1,430,860 (B) 
1,485,000 (A) 



0.963 = efficiency of joint 



APPENDIX 



103 



417 Figs. 28 and 29 illustrate other joints that may be used. 
The butt and double strap joint with straps of equal width shown in 
Fig. 28 may be so designed that it will have an efficiency of from 82 
to 84 per cent and the saw-tooth joint shown in Fig. 29 so that it will 
have an efficiency of from 92 to 94 per cent. 




Fig. 28 Illustration of Butt and Double Strap Joint with Straps of 

Equal Width 




Fig. 29 Illustration of Butt and Double Strap Joint of the Saw-Tooth 

Type 



104 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



Braced and Stayed Surfaces 

418 The allowable loads based on the net cross-sectional areas of 
staybolts with V-threads, are computed from the following formulae. 
The use of Whitworth threads with other pitches is permissible. 

The formula for the diameter of a staybolt at the bottom of a 
V- thread is: 

D — (P X 1-732) = d 
where 

D = diameter of staybolt over the threads, in. 
P = pitch of threads, in. 

d = diameter of staybolt at bottom of threads, in. 
1.73i2 = a constant 

When U. ,S. threads are used, the formula becomes 

D— (P X 1-73.2 X 0.75) = d 

Tables 11 and 12 give the allowable loads on net cross-sectional 
areas for staybolts with Y- threads, having 12 and 10 threads per inch. 



TABLE 11. ALLOWABLE LOADS ON STAYBOLTS WITH V-THREADS, 12 THREADS 

PER INCH 



Outside Diameter 


Diameter at 


Net Cross- 


Allowable Load 


of 


Bottom of 


Sectional Area 


at 7500 Lb. 


Staybolts, In. 


Thread, 


(at Bottom of 


Stress, per 


In. 


Thread), Sq. In. 


Sq. In. 


% 


0.7500 


0.6057 


0.288 


2160 


if 


0.8125 


0.6682 


0.351 


2632 


0.8750 


0.7307 


0.419 


3142 


& 


0.9375 


0.7932 


0.494 


3705 


i 


1.0000 


0.8557 


0.575 


4312 


1A 


1.0625 


0.9182 


0.662 


4965 


IV% 


1.1250 


0.9807 


0.755 


5662 


1A 


1 . 1875 


1.0432 


0.855 


6412 


1M 


1.2500 


1 . 1057 


0.960 


7200 


1A 


1.3125 


1 . 1682 


1.072 


8040 


l% 


1.3750 


1.2307 


1.190 


8925 


1A 


1.4375 


1.2932 


1.313 


9849 


iy 2 


1.5000 


1.3557 


1.444 


10830 



APPENDIX 



105 



TABLE 12. ALLOWABLE LOADS ON STAYBOLTS WITH V-THREADS, 10 THREADS 

PER INCH 





Diameter at 


Net Cross- 


Allowable Load 


of 


Bottom 


Sectional Area 


at 7500 Lb. 


Staybolts, In. 


of Thread, 
In. 


(at Bottom of 
Thread), Sq. In. 


Stress per 
Sq. In. 


1M 


1.2500 


1.0768 


0.911 


6832 


1A 


1.3125 


1.1393 


1.019 


7642 


l% 


1 . 3750 


1.2018 


1.134 


8505 


\i 


1.4375 


1.2643 


1.255 


9412 


1 . 5000 


1.3268 


1.382 


10365 


1& 


1 . 5625 


1.3893 


1.515 


11362 


m 


1 . 6250 


1.4518 


1.655 


12412 



419 Table 13 shows the allowable loads on net cross-sectional 
areas of round stays or braces. 



TABLE 13. ALLOWABLE LOADS ON ROUND BRACES OR STAY RODS 







Allowable Stress, in Lb. per Sq. In., Net Cross-sectional 


Minimum 


Net 




Area 










Diameter 
of Circular 


Cross-sectional 
Area of Stay, 


6000 


8500 


9500 


Stay, In. 


in Sq. In. 








Allowable Load, 


in Lb., on Net Cross-sectional Area 


1 1.0000 


0.7854 


4712 


6676 


7462 


1A 1.0625 


0.8866 


5320 


7536 


8423 


1H 1.1250 


0.9940 


5964 


8449 


9443 


1& 1.1875 


1 . 1075 


6645 


9414 


10521 


\Y* 1.2500 
l£ 1.3125 


1.2272 


7363 


10431 


11658 


1.3530 


8118 


11501 


12854 


iy 8 1.3750 


1.4849 


8909 


12622 


14107 


1& 1.4375 


1.6230 


9738 


13796 


15419 


iy 2 1.5000 


1.7671 


10603 


15020 


16787 


1* 1.5625 


1.9175 


11505 


16298 


18216 


\% 1.6250 


2.0739 


12443 


17628 


19702 


ltt 1.6875 


2.2365 


13419 


19010 


21247 


IH 1.7500 


2.4053 


14432 


20445 


22852 


1H 1.8125 


2.5802 


15481 


21932 


24512 


V/s 1.8750 


2.7612 


16567 


23470 


26231 


1H 1.9375 


2.9483 


17690 


25061 


28009 


2 2.0000 


3.1416 


18850 


26704 


29845 


1Y % 2.1250 


3.5466 


21280 


30147 


33693 


2H 2.2500 
2% 2.3750 


3.9761 


23857 


33797 


37773 


4.4301 


26580 


37656 


42086 


2y 2 2.5000 


4.9087 


29452 


41724 


46632 


2% 2.6250 


5.4119 


32471 


46001 


51413 


2% 2.7500 


5.9396 


35638 


50487 


56426 


2% 2.8750 


6.4918 


38951 


55181 


61673 


3 3.0000 


7.0686 


42412 


60083 


67152 



420 Table 14 gives the net areas of segments of heads for use in 
computing stays. 



106 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 
TABLE 14. NET AREAS OF SEGMENTS OF HEADS 



Height 










Diame 


,er of Boiler, In. 










from 




























Tubes 
to 


24 


30 


36 


42 


48 


54 


60 


66 


72 


78 


84 


90 


96 


Shell, 


























In. 








Area to be stayed, Sq. 


In. 










8 


28 


33 


37 


40 


43 


47 


51 


53 


55 


58 


60 


63 


65 


SH 


35 


41 


46 


51 


55 


59 


63 


66 


70 


74 


76 


80 


82 


9 


42 


49 


56 


62 


67 


72 


76 


82 


86 


90 


92 


95 


98 


93^ 


50 


58 


66 


70 


80 


86 


91 


96 


101 


105 


111 


116 


119 


10 


57 


68 


77 


85 


93 


99 


106 


112 


117 


123 


129 


132 


137 


10>2 


03 


78 


89 


98 


107 


114 


123 


131 


135 


142 


147 


153 


160 


11 


74 


88 


100 


111 


121 


130 


138 


147 


155 


161 


169 


174 


183 


IVA 


83 


99 


112 


124 


137 


146 


156 


165 


173 


181 


189 


196 


204 


12 


91 


109 


125 


139 


151 


103 


174 


184 


194 


203 


213 


219 


230 


i2y 2 




120 


138 


153 


167 


180 


193 


204 


216 


224 


234 


243 


252 


13 




132 


151 


108 


183 


197 


211 


224 


235 


247 


256 


267 


279 


13^ 




143 


164 


183 


200 


216 


230 


240 


258 


270 


282 


293 


302 


14 




155 


178 


199 


217 


234 


250 


200 


280 


294 


305 


319 


331 


UVa 




167 


192 


215 


235 


254 


271 


287 


303 


318 


333 


345 


360 


15 




178 


206 


231 


252 


273 


291 


309 


326 


343 


357 


372 


386 


15}* 






220 


217 


271 


291 


312 


332 


350 


368 


382 


400 


417 


16 






235 
249 
204 


203 
231 
297 


289 
308 
326 


312 
332 
353 


334 
357 
378 


355 
380 
402 


374 
399 
425 


394 
420 
447 


411 
436 

467 


423 
457 
486 


443 


16H 
17 






475 






502 


173^ 








314 


345 


374 


400 


426 


449 


471 


494 


516 


536 


18 








331 
349 
306 
384 
401 


365 
384 
404 
424 
444 
404 


396 
417 
439 
461. 

483 
505 


424 
448 
■470 
496 
519 
543 


450 
476 
500 

528 
552 
578 


476 
501 
529 
558 
583 
613 


500 
520 
555 
584 
613 
643 


520 
552 
580 
613 
642 
675 


543 

577 
604 
641 
667 
706 


564 


18M 








598 


19 








631 


19^ 








663 


20 








699 


203^ 








729 


21 










485 
505 


528 
551 


5G8 
594 


604 
632 


640 
669 


673 
703 


705 
739 


733 

706 


766 


21 H 










797 


22 










526 


574 

597 


018 
043 


"658 
687 


697 
726 


734 
765 


769 
800 


800 
835 


835 


223^ 










867 


23 












620 
642 
667 
689 
714 
737 
761 


008 
695 
719 
745 
771 
798 
824 
850 
877 
904 
930 


713 

740 

708 

797 

825 

855 

882 

909 

939 

908 

997 

1028 

1056 

1084 

1115 


754 

784 

814 

843 

875 

907 

936 

968 

998 

1030 

1060 

1092 

1123 

1155 

1187 

1218 

1252 

1286 

1317 


796 

827 

859 

892 

922 

956 

987 

1024 

1053 

1089 

1120 

1157 

1187 

1221 

1255 

1290 

1324 

1359 

1394 

1430 

1465 

1500 

1536 


830 
866 
897 
934 
966 
1003 
1035 
1073 
1106 
1145 
1177 
1211 
1248 
1284 
1321 
1358 
1394 
1433 
1467 
1508 
1542 
1578 
1617 
1654 
1692 


869 
904 
939 
975 
1010 
1047 
1083 
1120 
1157 
1195 
1232 
1270 
1305 
1347 
1382 
1424 
1459 
1496 
1538 
1575 
1617 
1655 
1695 
1735 
1775 
1810 
1857 


906 


233^ 
24 












945 












978 


24 K 












1018 


25 












1051 


2bY 2 












1092 


26 












1126 


26K 












1167 


27 














1202 


27^ 














1243 


28 














1279 


28>i 














1321 


29 
















1360 


29^ 
















1400 


30 
















1442 


30}4 
















1480 


31 


















1523 


31H 


















1561 


32 


















1605 


32 M 


















1650 


33 




















1687 


33^ 




















1733 


34 




















1770 


34^.. 




















1816 


35 






















1856 


35^. . 






















1900 


36 
























1941 


36^ 
























1984 


37 


























2026 































appendix 107 

Safety Yalves 

421 Method of Computing Table 8. The discharge capacity of 
a safety valve is expressed in equations 2 and 3 as the product of C 
and H. The discharge capacities are given in Tahle 8 for each valve 
size at the pressures shown and are calculated for various valve sizes, 
pressures and for three different lifts. The discharge capacities are 
proportional to the lifts, so that intermediate values may be obtained 
from the Table by interpolation. 

C = total weight or volume of fuel of any kind burned per 
hour at time of maximum forcing, lb. or cu. ft. 

H — the heat of combustion, B.t.u. per lb. or cu. ft. of fuel 
used. 

I) = diameter of valve seat, in. 

L = vertical lift of valve disc, in., measured immediately after 
the sudden lift due to the pop. 

P = absolute boiler pressure or gage pressure plus 14.7 lb. per 
sq. in. 

1100 = the number of B.t.u. required to change a pound of feed 
water at 100 deg. fahr. into a pound of steam. 

The boiler efficiency is assumed as 75 per cent. 

The coefficient of discharge, in Napier's formula, is taken as 96 
per cent. 

CXffXO.75 3.1416X£>X£X0.707X- p X0- 9 fl for valve with 
1100X3600 - 70 45-deg. seat.(l) 

CH = 160,856XPX#X-£ for valve with bevel seat at 45 deg.(2) 
07r=2.27,487X^X#X£ for valve with flat seat at 90 deg.(3) 

Method of Checking the Safety Valve Capacity by Measuring 
the Maximum Amount of Fuel that can be Burned 

422 The maximum weight of fuel that can be burned is deter- 
mined by a test. The weight of steam generated per hour is found 
from the formula : 

F= noi) ~ where 



108 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

W = weight of steam generated per hour, lb. 

C = total weight of fuel burned per hour at time of maxi- 
mum forcing, lb. 

H = the heat of combustion of the fuel, B.t.u. per lb. (see 
Par. 427). 

The sum of the safety valve capacities marked on the valves as 
provided for in the Eules shall be equal to or greater than the maxi- 
mum evaporative capacity of the boiler. 

Table 8 may be used for determining the number of safety valves 
required as illustrated in the following examples : 

423 Example 1 : A boiler at the time of maximum forcing uses 
2150 lb. of Illinois coal per hour of 12,100 B.t.u. per lb. Boiler pres- 
sure, 2-25 lb. per sq. in. gage. 

2150X12,100 = OH = 26,015,000 

Table 8 shows that two 3y 2 -m. bevel seated valves with 0.11 in. 
lift, or one 3-in. bevel seated valve with 0.10 in. lift and one 3y 2 -m. 
bevel seated valve with 0.11 in. lift, would discharge the steam gen- 
erated. 

424 Example 2: Wood shavings of heat of combustion of 6400 
B.t.u. per lb. are burned under a boiler at the maximum rate of 2000 
lb. per hour. Boiler pressure, 100 lb. per sq. in. gage. 

2000X6400 = CH = 12,800,000 

Table 8 shows that two 3%-in. bevel seated valves with 0.11 in. lift, 
or one 3-in. bevel seated valve with 0.08 in. lift and one 4-in. bevel 
seated valve with 0.12 in. lift, would discharge the steam generated. 

425 Example 3: An oil-fired boiler at maximum forcing uses 
1000 lb. of crude oil (Texas) per hour. Boiler pressure. 275 lb. per 
sq. in. gage. 

1000X18,500 = CH= 18,500,000 

Table 8 shows that two 3y 2 -m. bevel seated valves with 0.06 in. 
lift, or two 3-in. flat seated valves with 0.05 in. lift, or two 2%-in. 
flat seated valves with 0.06 in. lift, would discharge the steam gen- 
grated. 

426 Example k : A boiler fired with natural gas consumes 3000 
cu. ft. per hour. The working pressure is 150 lb. per sq. in. gage. 

3000X960 = CH= ,2,880,000 



APPENDIX 



109 



Table 8 shows that two l|-in. bevel seated valves with 0.05 in. 
lift, or two 1-in. flat seated valves with 0.04 in. lift, would discharge 
the steam generated. 

*427 For the purpose of checking the safety valve capacity as 
described in Par. 422, the following UNIT values of heats of com- 
bustion of various fuels in B.t.u. may be used: 

B.t.u. 
per lb. 

Semi-bituminous coal 14,500 

Anthracite .— — 13,700 

Screenings 12,500 

Coke 13,500 

Wood, hard or soft, kiln dried 7,700 

Wood, hard or soft, air dried 6,200 

Shavings 6,400 

Peat, air dried, 25 per cent moisture 7,500 

Lignite 10,000 

Kerosene _ 20,000 

Petroleum, crude oil, Penn 20,700 

Petroleum, crude oil, Texas 18,500 

Petroleum, crude oil, California 18,500 

B.t.u. 

per cu. ft. 

Natural gas 960 

Blast furnace gas 100 

Producer gas 150 

Water gas, uncarburetted — 200 

♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



110 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 



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112 



REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 




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appendix 118 

Fusible Plugs 

428 Fusible plugs, if used, shall be filled with tin with a 
melting point between 400 and 500 deg. Fahr. 

*428a Fusible plugs may be used, and if so used and installed 
after these Orders become effective, shall conform to Pars. 429-430 
of the A.S.M.E. Code. 

429 The least diameter of fusible metal shall be not less than 
■J in., except for maximum allowable working pressures of over 
175 lb. per sq. in. or when it is necessary to place a fusible plug in a 
tube, in which case the least diameter of fusible metal shall be not 
less than § in. 

430 Each boiler may have one or more fusible plugs, located as 
follows : 

a In Horizontal Return Tubular Boilers — in the rear head, 
not less than 2 in. above the upper row of tubes, the meas- 
urement to be taken from the line of the upper surface of 
tubes to the center of the plug, and projecting through 
the sheet not less than 1 in. 

b In Horizontal Flue Boilers — in the rear head, on a line with 
the highest part of the boiler exposed to the products of 
combustion, and projecting through the sheet not less 
than 1 in. 

c In Traction, Portable, or Stationary Boilers of the Loco- 
motive Type or Star Water Tube Boilers — in the highest 
part of the crown sheet, and projecting through the sheet 
not less than 1 in. 

d In Vertical Fire-tube Boilers — in an outside tube, not less 
than one-third the length of the tube above the lower 
tube sheet. 

e In Vertical Fire-tube Boilers, Corliss Type — in a tube, not 
less than one-third the length of the tube above the lower 
tube sheet. 

/ In Vertical Submerged Tube Boilers — in the upper tube 
sheet, and projecting through the sheet not less than 1 in. 

g In Water-tube Boilers, Horizontal Drums, Babcock & Wil- 
cox Type — in the upper drum not less than 6 in. above 
the bottom of the drum, over the first pass of the pro- 
ducts of combustion, and projecting through the sheet 
not less than 1 in. 

h In Stirling Boilers, Standard Type — in the front side of 
the middle drum, not less than 4 in. above the bottom of 
the drum, and projecting through the sheet not less than 
lin. 



♦Indicates changes by the Industrial Accident Commission of the State of 
California. 



114 REPORT OF BOILER CODE COMMITTEE, AM.SOC.M.E. 

i In Stirling Boilers, Superheater Type — in the front drum, 
not less than 6 in. above the bottom of the drum, exposed 
to the products of combustion, and projecting through the 
sheet not less than 1 in. 

j In Water-tube Boilers, Heine Type — in the front course of 
the drum, not less than 6 in. above the bottom of the drum, 
and projecting through the sheet not less than 1 in. 

Te In Bobb-Mumford Boilers, Standard Type — in the bottom 
of the steam and water drum, 24 in. from the center of the 
rear neck, and projecting through the sheet not less than 
1 in. 

Z In Water-tube Boilers, Almy Type — in a tube or fitting ex- 
posed to the products of combustion. 

m In Vertical Boilers, Climax or Hazelton Type — in a tube or 
center drum not less than one-half the height of the shell, 
measuring from the lowest circumferential seam. 

n In Cahall Vertical Water-tube Boilers — in the inner sheet 
of the top drum, not less than 6 in. above the upper tube 
sheet, and projecting through the sheet not less than 1 in. 

o In Wickes Vertical Water-tube Boilers — in the shell of the 
top drum and not less than 6 in. above the upper tube 
sheet, and projecting through the sheet not less than 1 in, ; 
so located as to be at the front of the boiler and exposed to 
the first pass of the products of combustion. 

p In Scotch Marine Type Boilers — in the combustion chamber 
top, and projecting through the sheet not less than 1 in. 

q In Dry Back Scotch Type Boilers — in the rear head, not less 
than 2 in. above the upper row of tubes, and projecting 
through the sheet not less than 1 in. 

r In Economic Type Boilers— in the rear head, above the upper 
row of tubes. 

s In Cast-Iron (Sectional Heating Boilers — in a section over 
and in direct contact with the products of combustion in 
the primary combustion chamber. 

t In Water-tube Boilers, Worthington Type — in the front side 
of the steam and water drum, not less than 4 in. above the 
bottom of the drum, and projecting through the sheet not 
less than 1 in. 

u For other types and new designs, fusible plugs shall be placed 
at the lowest permissible water level, in the direct path 
of the products of combustion, as near the primary com- 
bustion chamber as possible. 



INDEX 



TO 

RULES FOR THE 

CONSTRUCTION OF STATIONARY BOILERS 

AND FOR ALLOWABLE WORKING 

PRESSURES 



Index to Complete Rules 117 

Index to Rules for New Installations of Power Boilers. . 131 

Index to Rules for New Installations of Heating Boilers 141 

Index to Rules for Existing Installations 145 



115 



INDEX TO COMPLETE RULES 



A PAGE 

Access and firing doors, power boilers 79 

Access and firing doors, heating boilers 86 

Adamson furnace , 62 

Additional safety valves, existing installations 92 

Adjustment of safety valves for blow down 74 

Age limit for lap seam boilers 89 

Allowable load on stay-bolts, table of 104 

loads on circular braces 105 

loads on stays, table of 105 

stress on stays 52 

stress on stays and stay-bolts 54 

working pressure, heating boilers 81 

working pressure, existing installations 89 

working pressure, existing installations, heating boilers 90 

working pressure, power boilers 43 

Altitude gages 85 

Angles on h.r.t. boiler heads, 36 in. or less diameter 56 

Area, grate surface, table to determine size of safety valves 84 

segment, formula for 54 

segments of heads to be stayed 53 

segments, table of 106 

to be stayed in heads • > • 53 

to be stayed in heads having manhole 54 

Automatic shut-off valves 75 

non-return stop valves 76 

B 

Back pitch of riveted joints , 44 

Bars, steel for boiler parts 7 

steel, specifications for 19 

refined iron, specifications for 37 

Beading of tube ends 64 

Blow down for safety valves 74 

Blow-off cock, power boilers 77 

existing installations 93 

heating boilers 86 

piping, new installations 76 

piping, existing installations 93-94 

piping, heating boilers 86 

pipe and fittings 77 

Broiler builder's stamps, location of 80 

builder's stamps, not to be covered 80 

bushing, for feed pipe connection 77 

plat© steel, specifications for 11 

to be stamped A.S.M.E. std. 79 

wet bottom, distance from floor line 79 

wet bottom, distance from floor line (heating boilers) 86 

Braced and stayed surfaces 49 

Braced and stayed surfaces 104 

117 



PAR. 

327-328 

370 

242 

393 

281 

380 

418-419 

419 

419 

209 

220 

338-340 

378-384 

383 

179-180 

362 

225-229 

356 

217 

214 

214-217 
218 
292 
303 



182 
6 
64- 76 
151-163 
250 
281 

309-311 
401-403 
364 

307-313 
401-405 
364 
311 
333 
334 
315 

23- r j 

332 

326 

369 

199-233 

418 



118 



INDEX TO COMPLETE RULES 



PAGE 

Braces, diameter of pins, area of rivets in and design of crowfeet for. ... 55 

made of steel plate . . . 7 

made of steel plate (gussets) 56 

spacing between 51 

steel bars for 7 

when welded 7 

Brackets, to support h.r.t. boilers 79 

Brown furnaces 63 

B.t.u. of various fuels 109 

Butt and double-strap joint 

double riveted 97 

triple riveted 98 

quadruple riveted 99 

quintuple riveted . 101 

Butt straps, tables of minimum thicknesses of. 9 

straps, to be rolled or formed 45 

straps, of equal width . . , 103 

straps, saw tooth 103 



Calking 65 

Capacity of safety valves 

examples of checking 108 

method of checking 107 

method of checking (existing installations) 91 

Cast iron (See gray iron castings or malleable castings) 

for headers 64 

used with superheated steam . . 8 

boiler, hydrostatic pressure test of 87 

boiler, maximum pressure allowed on 87 

boiler, section to be tested 87 

headers, maximum pressure allowed on, existing installations 90 

headers, maximum pressure allowed on, power boilers 64 

headers, tested to destruction . 64 

Cast steel (See steel) 

Castings, specifications for gray iron 26 

specifications for malleable iron 29 

specifications for steel . , . 22 

Channel irons for flat heads 50 

Check valve on feed-pipe 77 

Check valve on feed-pipe, existing installations C 3 

Chocking safety valve capacity, method of 1C7 

Checking safety valve capacity, method of, existing installations .91-92 

Circular furnaces and flues 61 

Circular manhole opening 65 

Circumferential joints 44 

Cleanout door in setting 79 

Cock (See valves, gage cocks, blow-off cocks) 

Combined area of safety valves. 74 

Combustion chamber, materials to be used in 7 

Combustion chamber, sling stays 60 

Combustion chamber, tube sheets of 59 

Cones, truncated, maximum allowable working pressure on 58 

Connections, flanged 82 

safety valve 73 

steam gages 75 

water column 78 

Contraction of steam mains, provision for 76 

Convex and concave heads • • • • 49 

Corrugated furnaces 63 

C :vors, manhole and handhole 7 



PAR. 

223 
5 

224 
203 

6 

4 

325 

243-244 

427 

413 
414 
415 
416 
19 
191 
417 
417 



257 

423-426 

422-427 
391-392 

246 
12 
372 
374 
372 
382 

245-247 
247 

95-110 
111-120 

77- 94 
201 
317 
406 

422-427 
391-392 
229-241 
258 

1S4-185 
327 

280 

2 
235-236 
2C4 
221 
346 

277-278 
296 

320-321 
305 
195 
243 

5 



INDEX TO COMPLETE RULES 119 

PAGE PAR. 

Covers, manhole, material 67 262 

Cross boxes, material of 8 9 

Cross pipes connecting steam and water drums, material of 8 9 

Crown bars and girder stays 58 230 

Crushing strength of steel plate 8 15 

Crushing strength of steel plate, existing installations 90 387 

Crushing strength, applied to joints 95 410 

Curved surfaces to be stayed. 58 230 



Damper regulator, connected to steam space 86 365 

Damper regulator, connected to water column 75 295 

Damper regulator, connected to water column, existing installations 92 397 

Diagonal braces 54 221 

stays, stresses in 54 221-222 

tube holes in shell or drum 47 193 

Dial of steam gage . . . . . 75 297 

Diameter of fusible metal in fusible plug 113 429 

Diameter of rivet holes, old boilers 91 388 

Direct spring-loaded, safety valve, construction of. 69 272 

Discharge capacity of safety valves 68 270-274 

Discharge pipe from safety valves 73 278-279 

Dished heads 49 195-198 

Dished heads, corner radius of 49 197 

Dished heads, with manhole opening 49 195 

Domes 48 194 

Door,, access and firing, minimum size of . . 79 327-328 

Door, access and firing, minimum size of, heating boilers 86 370 

Door, frame rings, material of 8 13 

Door latches 79 328 

Doubling plates 50 199 

Down-draft boilers, safety valves for 85 359 

Drains from stop valves 76 303-304 

from stop valves, existing installations 93 400 

from superheater 76 306 

Drilling rivet holes 65 253-254 

Drilling tube holes 64 248-249 

Drum or shell, longitudinal joints of (See joints) 45 187 

Drum, material of 7 2- 3 

E 

Edge of plate to center of rivet 44 183 

Edges of plates for calking 65 257 

Edges of tube holes to be removed 64 249 

Efficiency of ligament, between tube holes 46 192 

of ligament, between diagonal tube holes 47 193 

of riveted joints 44 181 

of riveted joints, to calculate 95-103 410-417 

Elbow on escape pipe, from safety valve 73 279 

Elliptical manhole, size of 65 258 

End of feed pipe, to be open 77 314 

Ends of stay-bolts, to be riveted over 50 200 

of stays below tubes 53 216 

of tubes, fire-tube boilers 64 250 

of tubes, water-tube boilers, and superheaters . 64 251-252 

Equalizer, to support h.r.t. boilers 78 324 

Escape pipe, from safety valve 73 278-279 

Escape pipe, from safety valve, existing installations 92 394 

Escape pipe, from safety valve, heating boilers 83 355 

Examples of checking safety valve capacities 108 423-426 

Existing installations 89-94 378-409 



120 INDEX TO COMPLETE RULES 

PAGE PAR. 

Existing installations, steam heating boilers 90 383 

Expansion of steam mains, provisions for 76 305 

Extra heavy fittings on blow-off 77 310-311 

Extra thick tube, for fusible plug 113 429 

F 

Factors of safety 

for domes when single riveted 48 194 

existing boilers 89 379 

new installations 43 180 

second hand boilers 90 381 

steel heating boilers , 81 340 

Feed pipe, ends to be open 77 314 

Feed pipe, fittings -and valves on 77 317 

Feed piping, power boilers 77 314-318 

piping, existing installations 94 406 

water discharge 77 315 

water, discharge clear of joints 77 316 

water regulator, connection to 75 295 

water supply apparatus 78 318 

Fire-box steel, for shells, drums 7 2 

box steel, specifications for 11 23— 39 

brick casing, for blow-off pipe 77 312 

tube boiler, manhole in 67 264 

tube boiler, thicknesses of tubes of 10 22 

Firing doors 79 327-328 

Fittings and appliances, existing installations 92 395-407 

Fittings and appliances, heating boilers 66 364-368 

Fittings and appliances, power boilers 76 299-322 

Flange fittings, tables of sizes of 110-111 

of manhole opening 54 218 

(Steel, for heating boilers 81 337 

steel, for shells, drums 7 3 

steel specifications for 11 23- 39 

Flanged connections, heating boilers. . 82 346 

Flanged construction for water leg and door frame ring:; 8 13 

Flanges, cast iron, thickness of 76 299 

Flanges, reinforcing, thickness and material of 68 268 

Flaring of tube ends 64 251 

Flat surfaces, to be stayed 49 199 

Flat surfaces, to be stayed between tubes and between tubes and shell. ... 53 216 

Flues, circular, pressure allowed on 61 241 

Fox furnaces 63 243-244 

Fuels, heats of combustion of 109 427 

Furnace sheets, stamps to be visible on 79 331 

Furnaces: 

Adamson type 62 242 

Brown 63 243 

circular flues 61 241 

corrugated 63 243 

Fox 63 243 

internal cylindrical, staying of 52 212 

Leeds suspension bulb 63 243 

material of 7 2 

Morison 63 243 

plain circular 61 239-240 

Purves 63 243 

thickness of corrugated or ribbed 64 244 

vertical boilers . 60 237-238 

Fusible plugs 113 428-430 

Fusible plugs, location of 113 430 



INDEX TO COMPLETE RULES 121 

G PAGE PAB. 

Gage, altitude 85 362 

cocks, existing installations 93 396 

cocks, heating boilers 86 367 

cocks, power boilers 75 294 

inspector's, connection for 75 298 

steam and connections, existing installations 93 398 

steam and connections, heating boilers 85 361 

steam and connections, power boilers 75 296 

steam, dial of 75 297 

water, glass, existing installations 92-93 395-396 

water, glass, heating boilers 86 366 

water, glass, power boilers 75 291-295 

Gas fired boilers, safety valves for 85 360 

Girder stays and crown bars 58 230 

Globe valve, not to be used on blow-off, 77 308 

Globe valve on feed pipe 77 314 

Grate surface, table of, for safety valves 84 358 

Gray iron castings, specifications for 26 95-110 

Gusset stays, stresses in 54 221-224 

H 

Handhole covers, material 7 5 

Handholes, in h.r.t. boilers . 67 264 

in locomotive type boiler 67 265 

in vertical fire engine boilers . . . 67 267 

in vertical fire tube boilers 67 266 

Headers, cast iron, existing installations 90 3*82 

cast iron, new boilers 64 245 

cast iron, pressure allowed on 64 245-247 

and pressure parts, material of 8 9 

Heads, angles for staying upper segments 56 225-229 

area of segments to be stayed 53 213—214 

217 

area of segments to be stayed, table for 106 420 

convex and concave 49 195-198 

segments of, area to be stayed 53 213-214 

217 

stamps to be visible 79 331 

stiffeners for : 50 201 

Heating boilers 81 335-377 

Heating boilers, existing installations 90 383-384 

Heating boilers, to which the rules of power boilers shall apply 81 335 

Heat of combustion of various fuels. 109 427 

Holes for rivets 65 254 

for screw stays 52 210 

for wash-out, heating boilers 82 345 

for wash-out, power boilers 67 265-267 

Horizontal return tubular boilers: 

location of feed-water discharge 77 315 

longitudinal joints, to be above fire line 45 189 

manhole below tubes 67 264 

maximum length of joint 45 190 

method of supporting 78 323-324 

staying heads of, 36 in or less 56 225 

water column connections 78 320 

Hot water boilers 81 335-377 

Hydrostatic pressure test 

of cast iron headers 64 247 

heating boilers . 87 372-374 

old boilers 94 408-409 

power boilers 79 329-330 

on sections of cast iron boiler 87 372 



122 INDEX TO COMPLETE RULES 

I PAGE 

Inspection at shop, heating boilers 87 

Inspector's test gage connection 75 

Inspirator or injector, used to feed boiler 78 

Insulating material, not to cover boiler stamps 80 

Internal pipe, in steam space 75 

Iron, cast (See cast iron) 

for stay bolts, specifications for 34 

rivets, specifications for 01 

rivets, shearing strength of 8 

wrought, stays and stay bolts 7 

-wrought, stays and stay bolts, specifications 34 

wrought, tensile strength, existing installations 90 

wrought, water leg and door frame rings 8 

J 

Joints, back pitch 44 

Joints, butt and double strap, double riveted, example of . . . . 97 

butt arid double strap, triple riveted, example of 98 

butt and double strap, quadruple riveted, example of 99 

butt and double strap, quintuple riveted, example of. 101 

butt and double strap, required on shell or drum over CG in. diameter 45 

calking of .» 65 

circumferential 44 

of domes 48 

efficiency of 44 

efficiency of, detailed methods of calculation 95 

existing boilers 89 

heating boilers 82 

lap, double riveted, longitudinal or circumferential, example of 96 

lap crack 90 

lap riveted, allowed on shell or drum not over 36 in. diameter 45 

lap riveted, allowed on domes 48 

lap single riveted, longitudinal or circumferential, example of 96 

longitudinal 45 

longitudinal lap joints on heating boilers . 82 

longitudinal, location of rivet holes on 44 

longitudinal of furnace v.t. boiler to be staybolted 60 

longitudinal of h.r.t. boiler to be above the fire line 45 

longitudinal of h.r.t. boiler to be above the fire line, heating boilers. . 86 

longitudinal, maximum length of 45 

longitudinal, maximum length of, heating boilers 82 

power boilers . . . . 44 

protection of 82 

welded .'... 45 

L 

Lamphrey fronts, valves on 78 

Lamphrey fronts, valves on, existing installations 94 

Lap joint crack 90 

Lap joints: 

length of, heating boilers 82 

length of, power boilers 45 

longitudinal or circumferential, single riveted 96 

longitudinal or circumferential, double riveted 96 

longitudinal domes 48 

longitudinal hot water boilers 82 

longitudinal lap crack 90 

longitudinal, steam heating boilers 82 

Lap welded tubes, specifications for 40 

Latches, door 79 



PAR. 
375 

298 
318 
334 
290 

139-150 
121-138 

16 
7 
139-150 
385 

13 



182 

413 

414 

415 

416 

187 

257 

184-185 

198 

181 

410 

380 

341-344 

412 

384 

188 

194 

411 

187-191 

341 

183 

238 

189 

371 

190 

342 

181-191 

344 

186 



319 

407 
384 

342 

190 

411 

412 

194 

343 

384 

341 

164-178 

328 



INDEX TO COMPLETE RULES 123 

PAGE PAR. 

Laying out shell plates, furnace sheets and heads 79 331 

Leeds suspension bulb furnaces 63 243 

Length of stays between supports 54 220 

Ligament between tube holes, efficiency of 46 192-193 

Lead allowed on stay-bolts 54 220 

Location of A.S.M.E. stamp 80 333 

of domes 48 194 

of fusible plugs . . . . 113 430 

Locomotive type boiler, water leg and door frame rings. 8 13 

Longitudinal joints 45 187—191 

steam heating boilers 82 341 

hot water boilers 82 343 

lap crack 90 384 

on domes 48 194 

of h.r.t. boilers to be above fire line, heating boilers 86 371 

of h.r.t. boilers to be above fire line, power boilers 45 189 

Low pressure steam boiler . 81 335-377 

Lugs, made of steel plate 7 5 

Lugs, to support h.r.t. boilers 78 323-325 

M 

Main steam pipe, stop valve on... 76 301-304 

Malleable . castings, specifications for 29 111-120 

Manholes 65 258-264 

below tubes, h.r.t. boiler 67 264 

below tubes, h.r.t. boiler, staying of . . . 54 218 

covers, material of 67 262 

covers, when plate steel 7 5 

in a dished head : 49 198 

frame, riveting of 65 260 

frame, proportions of 66 261 

gaskets, bearing surface of 67 263 

in any fire tube boiler, over 40 in. diameter 67 264 

in dome heads 67 264 

openings, minimum sizes of 65 258 

plates, material of 67 262 

reinforcement, material of 65 259 

reinforcement, on boiler 48 in. diameter or over 65 260 

Manufacture (See specifications) 

Manufacturer's name, heating boilers 87 377 

Manufacturer's stamp 79 332 

Manufacturer's stamp not to be covered 80 334 

Materials, selection of 7 1-13 

Materials, selection of, for heating boilers 81 335-337 

Maximum allowable working pressure 

braced and stayed surfaces 49 199 

existing boilers 89 378-384 

heating boilers 81 338-340 

shells of power boilers 43 179-180 

Methods of support 78 323-325 

Morison furnaces 63 243-244 

Mud drums, maximum allowable working pressure 90 382 

Mud drums, material of 8 10 

Muffler on safety valves 73 279 

N 

Name, manufacturers, on heating boilers 87 377 

Non-return stop valves, automatic 76 303 

Nozzles, material of 8 12 

Nozzles, and fittings : 76 299 

Number of gage cocks 75 294 

Numbers, serial 79 332 



124 INDEX TO COMPLETE RULES 

PAGE PAR. 

OG flanged construction 8 13 

Oil-fired boilers, safety valves for 85 360 

Openings, flanged connections, heating boilers 82 346 

Openings, threaded to be reinforced 68 268 

Outside screw and yoke valves, on steam pipe 76 301 

Outside screw and yoke valves, on water column 75 293 

P 

Pins in braces, diameter of 55 223 

Pipes, bottom blow-off and fittings, existing installations 93-94 401-405 

bottom blow-off and fittings, heating boilers 86 SC4 

bottom blow-off and fittings, power boilers 77 308 

feed and fittings 77 314-317 

in steam space 75 290 

main steam, valves on 70 301 

or nipple, number of threads into fitting 76 300 

or nipple, number of threads into fitting, tablo. . . 68 268 

surface blow-off and fittings 76 307 

threads, minimum number of 68 268 

water column, and fittings 78 320 

Piping, feed 77 314-318 

Pitch of rivets 44 182 

of rivets 95 410 

of stay-bolts 50 199 

of stay-bolts, table 51 203 

of stay tubes 59 233 

Planing edges of plates 65 257 

Plate, steel, specifications for 11 23- 39 

Plates, thickness, in shell or dome after flanging 9 18 

minimum thickness of in a boiler 9 17- 20 

minimum thickness of stayed flat surface 49 199 

Plugs, fusible 113 428-430 

Power boilers 7-80 1-334 

Power boiler requirements for certain heating boilers. 81 335 

Pressure, allowed on cast iron boilers ■. 81 338 

allowed on shell or drum, formula for existing installations 89 378 

allowed on shell or drum, formula for, power boilers 43 180 

maximum allowable working, on flat surfaces, power boilers 49 199 

maximum allowable working, old boilers 89 378-384 

maximum allowable working, old boilers steam heating 90 383 

maximum allowable working, heating boilers 81 338-340 

maximum allowable working, on shells, power boilers 43 179-180 

parts over 2 in., material of 8 9 

parts of superheaters, material of 8 11 

Protection of joints 82 344 

Pump, to supply feed water 78 318 

Purves furnaces 63 243 

R 

Regulators, damper ." 86 365 

Reinforced threaded openings in shell, heads of drums 68 268 

Relief valves for hot water boilers 83 349-350 

Reservoirs, on steam mains 76 305 

Rings, waterleg and door frame, material of 8 13 

Rivet holes, finish and removal of burrs 65 253-254 

iron, specifications for 31 121-138 

steel, specifications for . . . 15 40- 62 

Riveted joints (See joints) 

Riveting 65 253-256 



INDEX TO COMPLETE RULES 125 

Rivets PAGB PAR. 

allowable shearing strength of .8 10 

allowable shearing strength of, existing installations 90 386 

existing boilers, diameter of 90 388 

in braces, area of 55 223 

in shear on lugs or brackets 79 325 

in shear on manhole frames 65 260 

length of and heads for . . 65 255 

machine driven 65 256 

material of 8 8 

to completely fill rivet holes 65 255 

Rolling, ends of shell plates . 45 191 

S 

Safety, factor of 

for existing boilers 89 379 

for existing lap joint boilers 89 380 

for power boilers 43 180 

for steel heating boilers 81 340 

Safety valves 

additional on existing installations 92 393 

blow-down adjustment 74 281 

capacity, method of checking 107 422-427 

connections, existing boilers 92 394 

connections, heating boilers 83 347 

connections, power boilers 73-74 27C-278 

280 
289-290 

construction 74 282-287 

construction, heating boilers 84 356-358 

discharge capacity, existing boilers 91—92 391-392 

discharge capacity, power boilers 68 270-274 

discharge capacity, table of 70—72 

escape pipe for 73 278 

escape pipe for, existing installations 92 394 

escape pipe for, heating boilers 83 355 

for down draft boilers 85 359 

for existing installations 91 389-394 

for heating boilers 83 347-360 

for oil and gas fired boilers 85 360 

formula for 107 421 

formula for heating boilers 83-84 351-358 

method of computing and checking 107 421-427 

method of computing and checking, existing installations 91-92 391-392 

muffler on 73 279 

muffler on, existing installations •. 92 394 

power boilers 68 269-290 

required on boiler 68 269 

required on boiler, existing installations 91 390 

required on heating boilers 83 348 

seats of , 69 272 

seats of heating boilers 84 357 

setting of 68 271-281 

setting of, existing installations 91 390 

setting of, existing installations, heating boilers 83 348 

size limits, heating boilers 83 351 

size limits, power boilers 69 272 

stamping of 69 273 

stamping of, heating boilers 84 357 

superheater 74 288-289 

tattle of, for heating boilers 84 356 

test of 73 275 

testing of existing installations 91-92 391 



126 



INDEX TO COMPLETE RULES 



PAGE PAR. 

Saw-tooth type of butt and double strap joint. . 103 417 

Screwed stays, supporting of 54 219 

Seamless tubes, specifications for 40 164-178 

Seats of safety valves 69 272 

Second hand boilers 90 381 

Sections of cast iron, to be tested , 87 372 

Segment, area to be stayed 53 214-217 

of head, to be stayed : 53 213 

method of determining net areas, water tube boilers 53 215 

Segments, table of 106 420 

Selection of material . 7 1-13 

Serial number 79 332 

Setting of safety valves 68 271 

of safety valves, existing installations 91 390 

of safety valves, existing installations, heating boilers 83 348 

Setting, method of, wet bottom heating boilers 86 369 

Setting, method of, wet bottom power boilers 79 326 

Settings, heating boilers - 86 369-371 

Settings, power boilers 78 323-328 

Shearing strength of rivets 8 16 

Shearing strength of rivets, existing installations 90 386 

Shell or drum, longitudinal joints of 45 187-190 

or drum, to determine alowable pressure on, new boilers. . 43 180 

■or drum, to determine allowable pressure on, existing boilers 89 378 

plate, thickness of 9 17- 20 

Shut-off valves on water column pipes 75 293 

Shop inspection of heating boilers 87 375 

Sizes of flanged fittings, tables 110-111 

Sling stays 60 235-236 

Specifications for gray iron castings 26 95-110 

lap welded and seamless boiler tubes 40 164-178 

material, heating boilers . . . . 81 336 

malleable castings 29 111-120 

plate steel 11 23- 39 

refined wrought iron bars 37 151-153 

rivet iron 31 121-138 

rivet steel 15 40- 62 

stay bolt iron 34 139-150 

stay bolt steel 19 63 

steel bars 19 64- 76 

steel castings 22 77-94 

Stamping boilers A.S.M.E. std -. ,- 79 332 

Stamps, A.S.M.E. std., location of 80 333 

Stamps, not to be covered by insulation 80 334 

Stamps, to be visible on shell plates, furnaces sheets and heads 79 331 

Stay bolted surface, to compute allowable pressure on 49 199 

Stay bolts 

adjacent to edges of stay-bolted surface 51 205 

adjacent to furnace door or other opening •. . . . 52 206 

adjacent to furnace joint, v.t. boiler 60 238 

diameter of, how measured . .-. ........ 52 208 

ends of 50 200-202 

211 

holes for 52 210 

iron, specifications for 34 139-150 

material of 7 7 

maximum allowable stress on 54 220 

pitch of 49 199-204 

steel, specifications for 19 63 

tables of allowable load on 104 418-419 

Stared and braced surfaces 49 199-233 

Staved flat surface 49 199 



INDEX TO COMPLETE RULES 127 

PAGE PAR. 

Staying heads 55 222 

heads h.r.t. boiler 36 in. or less diameter 56 225-229 

dished heads 49 196 

furnaces 52 212 

segments of heads 53 213 

segments of heads with manhole opening 54 218 

Stay-rods, ends riveted over, to bo supported 54 219 

Stay-tubes 58 232-233 

Stays, crown bars and girders 58 230 

cross sectional area in calculating 52 209 

diagonal and gusset, stresses in 54 221-222 

224 

maximum allowable stress 54 220 

sling 60 235-236 

tables of allowable load on 104 418-419 

screwed, supporting of . . . 54 219 

upset for threading 52 211 

and stay-bolts, allowable stress on 54 220 

and stay-bolts, table of allowable stress on 104 418—419 

Steam gage end connections, existing installations 93 398— 398a 

gage and connections, heating boilers 85 361 

gage and connections, power boilers 75 296—298 

heating boilers, existing installations 90 383-384 

mains " 76 305 

mains, reservoirs on 76 305 

outlets 76 301 

outlets, existing installations 93 399 

Steel bars, for boiler parts 7 6 

castings, specifications for 22 77- 94 

crushing strength of plate 8 15 

for rivets, specifications for 15 40- 62 

for stay-bolts, specifications for 19 63 

plates exposed to fire 7 2 

plates when firebox quality not specified 7 3 

plates, shearing strength of 8 16 

stays and stay-bolts 49 199-212 

tensile strength of, existing installations 90 385 

wrought or cast, for boiler and superheater parts 8 11 

plate, crushing strength of 8 15 

plate, heating boilers 81 335-340 

plate, specifications for 11 23- 39 

plate, tensile strength of 8 14 

Stop valves (See valves) 

Straps, butt, of equal width 103 417 

Straps, butt, saw-tooth 103 417 

Superheater drains 76 306 

safety valve on 74 288-289 

tubes and nipples 64 251-252 

Superheaters and mountings, material for 8 11- 12 

Support, methods of, for boilers 78 323-326 

Support of stays, ends riveted over 54 219 

Surface blow-off 76 307 

Suspended type of setting h.r.t. boilers 78 324 

T 

Table of angles for staying heads 56 225 

constants for pitch of stay tubes 59 233 

discharge capacities of spring-loaded safety valves 69-70 

71-72 

flange fittings, standard 110 

flange fittings, extra heavy Ill 



128 



INDEX TO COMPLETE RULES 



PAGE PAR. 

Table of maximum allowable pitch of stay-bolts, ends riveted 51 204 

maximum allowable stresses for stays and stay-bolts 54 220 

minimum pipe threads for boiler connections . 68 268 

net areas of segments 106 420 

round braces or stay rods allowable loads 105 419 

sizes of safety valves, heating boilers 84 358 

sizes of rivets, existing boilers 90 388 

stay-bolts, allowable loads, 12 threads per inch 104 418 

stay-bolts, allowable loads, 10 threads per inch 105 418 

thickness of butt straps 9 19 

Tensile strength of steel or wrought iron, existing installations 90 385 

Tensile strength of steel plate 8 14 

Test, hydrostatic, of existing installations 94 408-409 

hydrostatic, of heating boilers 87 372-375 

hydrostatic, of power boilers 79 329-330 

of safety valve, existing installations 91—92 391 

of safety valve, power boilers ; 73 275 

of steam gage 75 298 

gage, connection for 75 298 

Thermometers on hot water boilers 86 363 

Thickness of corrugated or ribbed furnace 64 244 

required for boiler plates 9 17 

required for butt straps 9 19 

required for dome plates after flanging. . . 9 18 

required for shell plates 9 18 

required for tube sheets 9 20 

required for tubes 10 21- 22 

Threaded openings 68 268 

Threads, pipe or nipple into fitting. 76 300 

Threads, table 68 268 

Tin, for fusible plugs 113 428 

Truncated cones, maximum allowable working pressure on 58 231 

Tube ends, fire tube boiler 64 250 

ends, wafer tube boilers and superheaters 64 252 

for fusible plug 113 429 

heads, upper, staying segments of by steel angles 56 225-229 

heads, of water tube boilers 53 215 

holes and ends 64 248-252 

holes, diagonal, in shell or drum 47 193 

holes in shell or drum 46 192 

holes, sharp edges to be removed 64 249 

sheets of combustion chambers 59 234 

sheets, minimum thickness of. ... 9 20 

sheets, space allowed unstayed between tubes and between tubes and shell 53 216 

Tubes for fire-tube boilers, thicknesses of 10 22 

for water-tube boilers, thicknesses of 10 21 

lapwelded and seamless, specifications for 40 164-178 

required thickness 10 21- 22 

stay 58 232-233 

V 

Valves, automatic, on water glass. 75 292 

automatic non-return stop 76 303 

extra heavy, on bottom blow-off 77 311 

extra heavy, on main steam pipe 76 302 

globe, not to be used on blow-off • • • 77 308 

globe, on feed pipe 77 314 

on bottom blow-off 77 308-311 

on bottom blow-off, existing installations 93 401-403 

on every steam outlet 76 301 

on feed pipe 77 317 

on feed pipe, existing installations 94 406-4066 



INDEX TO COMPLETE RULES 129 

PAGE PAR. 

Valves, on Lamphrey fronts 78 319 

on Lamphrey fronts, existing installations 94 407 

outside screw and yoke type, on steam pipes 76 301 

outside screw and yoke type, on water column 75 293 

safety [See safety valves) 

stop , 76 301-304 

stop, drains for 76 303-304 

stop, existing installations 93 399 

stop, existing installations, drains 93 400 

Vertical boilers, furnaces of 60 237-238 

fire-tube boiler, manhole in • 67 264 

fire-tube boiler, waterleg and door frame ring 8 13 

W 

Washout holes, hot water boilers 82 345 

Washout holes, power boilers 67 265-267 

Water column and connections, existing installations 93 397 

column end connections, heating boilers 86 368 

column and connections, power boilers 75 295 

column and connections, power boilers 78 320—322 

glass and gage cocks, location of, power boilers 75 291-292 

glass, automatic valves not allowed 75 292 

glasses, existing installations 92 395 

glasses, heating boilers 86 366 

relief valves for hot water boilers 83 349-350 

Waterleg rings, material of 8 13 

Water tube boilers 

cast iron for headers of 64 246 

flaring of tube ends 64 251 

thicknesses of tubes of 10 21 

wrought or cast steel parts of 8 9 

Welded joints . . . - 45 186 

Welded stays 52 209 

Wet bottom boilers, height from floor line 79 326 

Wet bottom boilers, height from floor line, heating boilers 86 369 

Working pressure, maximum allowable 

existing installations 89 378-384 

power boilers 43 179-180 

steam and hot water boilers 81 338-340 

Wrought iron (See iron) 
Wrought steel (See steel). 



10— £5018 



INDEX TO RULES FOR NEW INSTALLA- 
TIONS OF POWER BOILERS 



A 

PAGE PAR. 

Access and firing doors, power boilers 79 327-328 

Adanison furnace 62 242 

Adjustment of safety valves for blow down 74 281 

Allowable load on stay-bolts, table of 104 418-419 

loads on circular braces 105 419 

loads on stays, table of 105 419 

stress on stays 52 209 

stress on stays and stay-bolts .- 54 220 

working pressure, power boilers 43 179-180 

Angles on h.r.t. boiler beads, 36 in. or less diameter 56 225-229 

Area of segment, formula for 54 217 

segments of beads to be stayed 53 214 

segments, table of 106 

to be stayed in heads 53 214-217 

to be stayed in beads having manhole 54 218 

Automatic shut-off valves 75 292 

non-return stop valves 76 303 

B 

Back pitch of riveted joints 44 182 

Bars, steel for boiler parts 7 6 

steel, specifications for 19 64- 76 

refined iron, specifications for 37 151-163 

Beading of tube ends '. 64 250 

Blow down for safety valves 74 281 

Blow-off cock 77 309-311 

piping new installations 76 307-313 

pipe and fittings 77 311 

Boiler, builder's stamps, location of 80 333 

builder's stamps, not to be covered 80 334 

bushing, for feed pipe connection 77 315 

plate steel, specifications for 11 23— 39 

to be stamped A. S. M. E. std 79 332 

wet bottom, distance from floor line 79 326 

Braced and stayed surfaces 49 199-233 

Braced and stayed surfaces 104 418 

Braces, diameter of pins, area of rivets in and design of crowfeet for. ... 55 223 

made of steel plate 7 5 

made of steel plate, gussets 56 224 

spacing between 51 203 

steel bars for 7 6 

when welded 7 4 

Brackets, to support h.r.t. boilers . 79 325 

Brown furnaces 63 243-244 

B.t.u. of various fuels 109 427 

Butt and double-strap joint, double riveted 97 413 

and double-strap joint, triple riveted 98 414 

and double-strap joint, quadruple riveted 99 415 

131 



132 



INDEX, NEW INSTALLATIONS OP POWER BOILERS 



PAGE 

Butt and double-strap joint, quintuple riveted 101 

straps, tables of minimum thicknesses of ...... , 9 

straps, to be rolled or formed 45 

straps of equal width. 103 

straps, saw tooth 103 



Calking . 65 

Capacity of safety valves, examples of checking 108 

Capacity of safety valves, method of checking. 107 

Cast iron (See gray iron castings or malleable castings) 

for headers 64 

used with superheated steam 8 

headers, maximum pressure allowed on, power boilers C4 

headers, tested to destruction 64 

Cast steel (See steel) 

Castings, specifications for gray iron t 26 

specifications for malleable iron. 29 

specifications for steel 22 

Channel irons for flat heads 50 

Check valve on feed-pipe 77 

Checking safety valve capacity, method of 107 

Circular furnaces and flues 61 

Circular manhole opening 65 

Circumferential joints 44 

Cleanout door in setting , 79 

Cock (See valves, gage cocks, blowoff cocks) 

Combined area of safety valves 74 

Combustion chamber, material to be used in 7 

Combustion chamber, sling stays : 60 

Combustion chamber, tube sheets of 59 

Cones, truncated, maximum allowable working pressure on 58 

Connections, safety valve 73 

steam gages 75 

water column 78 

Contraction of steam mains, provisions for 76 

Convex and concave heads 49 

Corrugated furnaces 63 

Covers, manhole and handhole 7 

Covers, manhole, material 67 

Cross boxes, material of 8 

Cross pipes connecting steam and water drums, material of 8 

Crown bars and girder stays 58 

Crushing strength of steel plate 8 

Crushing strength applied to joints 95 

Curved surfaces to be stayed 58 

D 

Damper regulator, connected to water column 75 

Diagonal braces 54 

stays, stresses in 54 

tube holes in shell or drum 47 

Dial of steam gage 75 

Diameter of fusible metal in fusible plug 113 

Direct spring-loaded safety valve, construction of ....*... 69 

Discharge capacity of safety valves 68 

Discharge pipe from safety valves 73 

Dished heads . . 49 

Dished heads, corner radius of 49 

Dished heads with manhole opening 49 

Domes 48 



PAK. 

416 
19 
191 
417 
417 



257 

423-426 

422-427 

246 
12 

245-247 

247 

95-110 
111-120 

77- 94 
201 
317 

422-427 
239-241 
258 

184-185 
327 

280 

2 
235-236 
234 
231 

277-278 
296 

320-321 
305 
195 
243 

5 
262 



230 

15 

410 

230 



295 

221 

221-222 

193 

297 

429 

272 

270-274 

278-279 

195-198 

197 

195 

194 



INDEX, NEW INSTALLATIONS OP POWER BOILERS 



133 



PAGE 

Door, access and firing, minimum, size of 79 

Door, frame rings, material of 8 

Door latches 79 

Doubling plates 50 

Drains from stop valves 76 

Drains from superheater 76 

Drilling rivet holes 65 

Drilling tube holes 64 

Drum or shell, longitudinal joints of (See joints) 45 

Drum, material of 7 

E 

Edge of plate to center of rivet, distance from 44 

Edges of plates for calking 65 

Edges of tube holes to be removed 64 

Efficiency of ligament, between tube holes 46 

of ligament, between diagonal tube holes 47 

of riveted joints 44 

of riveted joints, to calculate 95-103 

Elbow on escape pipe, from safety valve 73 

Elliptical manhole, size of 65 

End of feed pipe, to be open 77 

Ends of stay-bolts, to be riveted over 50 

stays below tubes 53 

tubes, fire-tube boilers 64 

tubes, water-tube boilers, and superheaters 64 

Equalizer, to support h.r.t. boilers 78 

Escape pipe, from safety valve 73 

Examples of checking safety valve capacities 108 

Expansion of steam mains, provisions for 76 

Extra heavy fittings on blow-off 77 

Extra; thick tube, for fusible plug 113 

F 

Factors of safety for domes when single riveted 48 

Factors of safety for new installations 43 

Feed pipe, ends to be open 77 

pipe, fittings and valves on 77 

piping, power boilers 77 

water, discharge 77 

water, discharge clear of joints 77 

water, regulator, connection to 75 

water, supply apparatus 78 

Fire-box steel, for shells, drums 7 

-box steel, specifications for 11 

brick casing, for blow-off pipe 77 

tube boiler, manhole in 67 

tube boiler, thicknesses of tubes of 10 

Firing doors 79 

Fittings and appliances, power boilers . 76 

Flange fittings, tables of sizes of 110-111 

of manhole opening . . . . 54 

steel for shells, drums 7 

steel specifications for 11 

Flanged construction for water leg and door frame rings 8 

Flanges, cast iron, thickness of 76 

Flanges, reinforcing, thickness and material of 68 

Flaring of tube ends 64 

Flat surfaces, to be stayed . > 49 

Flat surfaces, to be stayed between tubes and between tubes and shell .... 53 

Flues, circular, pressure allowed on 61 

Fox furnaces , 63 



PAR. 

327-328 

13 
328 
199 

303-304 
306 

253-254 
248-249 
187 
2- 3 



183 

257 

249 

192 

193 

181 

410-417 

279 

258 

314 

200 

216 

250 

251-252 

324 

278-279 

423-426 

305 

310-311 

429 



194 

180 
314 
317 

314-318 
315 
316 
295 
318 
2 

23- 39 
312 
264 

22 
327-328 
299-322 

218 
3 

23- 39 

13 
299 
268 
251 
199 
216 
241 
243-244 



134 INDEX, NEW INSTALLATIONS OF POWER BOILERS 

PAGE PAR. 

Fuels, heats of combustion of 1C9 427 

Furnace sheets, stamps to be visible on 79 331 

Furnaces 

Adamson type 62 242 

Brown 63 243 

circular flues 61 241 

corrugated 63 243 

Fox 63 243 

internal cylindrical, staying of 52 212 

Leeds suspension bulb 63 243 

material of 7 2 

Morison 63 243 

plain circular 61 239-240 

Purves 63 243 

thickness of corrugated or ribbed 64 244 

vertical boilers 60 237-238 

Fusible plugs .113 428-430 

Fusible plugs, location of 113 430 

G 

Gage cocks, power boilers 75 294 

inspector's, connection for 75 298 

steam and connections, power boilers 75 296 

steam dial of 75 297 

water, glass 75 291-295 

Girder stays and crown bars 58 2C0 

Globe valve, not to be used on blow-off 77 308 

Globe valve, on feed pipe 77 314 

Gray iron castings, specifications for 26 95-110 

Gusset stays, stresses in 54 221-224 

H 

Handhole covers, material 7 5 

Handholes, in h.r.t. boilers 67 264 

in locomotive type boilers 67 265 

in vertical fire engine boilers 67 267 

in vertical fire tube boilers 67 266 

Headers, cast iron, new boilers 64 245 

cast iron, pressure allowed on 64 245-247 

and pressure parts, material of 8 9 

Heads, angles of staying upper segments 56 225-229 

area of segments to be stayed 53 213-214 

217 

area of segments to be stayed, table for 106 420 

convex and concave 49 195-198 

segments of, area to be stayed. . 53 213—214 

217 

stamps to be visible 79 331 

stiffeners for 50 201 

Heat of combustion of various fuels 109 427 

Holes for rivets 65 254 

screw stays 52 210 

washout, power boilers 67 265-267 

Horizontal return tubular boilers 

location of feed-water discharge 77 315 

longitudinal joints, to be above fire line 45 189 

manhole below tubes 67 264 

maximum length of joint * 45 190 

method of supporting 78 323-324 

staying heads of, 36 in. or less 56 225 

water column connections 78 320 



INDEX, NEW INSTALLATIONS OF POWER BOILERS 135 

Hydrostatic pressure test PAGE par. 

of cast iron headers 64 247 

power boilers 79 329-330 

I 

Inspector's test gage connection 75 298 

Inspirator or injector, used to feed boiler 78 318 

Insulating material, not to cover boiler stamps 80 334 

Internal pipe, in steam space 75 290 

Iron, cast (See cast iron) 

for stay bolts, specifications for 34 139-150 

rivets, specifications for 31 121-138 

rivets, shearing strength of 8 16 

wrought, stays and stay bolts 7 7 

wrought, stays and stay bolts, specifications 34 139-150 

wrought, waterleg and door frame rings 8 13 

J 

Joints, back pitch 44 182 

butt and double strap, double riveted, example of 97 413 

butt and double strap, triple riveted, example of • 98 414 

butt and double strap, quadruple riveted, example of 99 415 

butt and double strap, quintuple riveted, example of 101 416 

Joints, butt and double strap, required on shell or drum over 36 in. diameter 45 187 

calking of 65 257 

circumferential 44 184-185 

of domes 48 198 

efficiency of 44 181 

efficiency of detailed methods of calculation 95 410 

lap, double riveted, longitudinal or circumferential, example of 96 412 

lap riveted, allowed on shell or drum not over 36 in. diameter '. 45 188 

lap riveted, allowed on domes 48 194 

lap, single riveted, longitudinal or circumferential, example of 96 411 

longitudinal 45 187-191 

longitudinal, location of rivet holes on 44 183 

longitudinal, of furnace, v.t. boiler to be stay-bolted 60 238 

longitudinal, of h.r.t. boiler to be above the fire line 45 189 

longitudinal, maximum length of 45 190 

power boilers 44 181-191 

welded 45 186 

L 

Lamphrey fronts, valves on 78 319 

Lap joints, length of, power boilers 45 190 

joints, longitudinal or circumferential, double riveted 96 412 

joints, longitudinal or circumferential, single riveted 96 411 

joints, longitudinal domes 48 194 

wolded tubes, specifications for 40 164-178 

Latches, door 79 328 

Laying out shell plates, furnace sheets and heads 79 331 

Leeds suspension bulb furnaces 63 243 

Length of stays between supports 54 220 

Ligament between tube holes, efficiency of 46 192-193 

Load allowed on stay-bolts 54 220 

Location of A. S. M. E. stamp 80 333 

domes 48 194 

fusible plugs 113 430 

Locomotive type boiler, water leg and door frame rings 8 13 

Longitudinal joints 45 187-191 

joints on domes 48 194 

joints of h.r.t. boilers to be above the fire line 45 189 

Lugs, made of steel plate 7 5 

Lugs, to support h.r.t. boilers 78 323-325 



136 INDEX, NEW INSTALLATIONS OF POWER BOILERS 

M PAGE PAK. 

Main steam pipe, stop valve on 76 301-304 

Malleable castings, specifications for 29 111-120 

Manhole in dome heads 67 264 

openings, minimum sizes of 65 258 

plates, material of 67 262 

reinforcement, material of 65 259 

reinforcement, on boiler 48 in. diameter or over 65 260 

Manholes 65 258-264 

below tubes, h.r.t. boiler 67 264 

below tubes, h.r.t. boiler, staying of 54 218 

covers, material of 67 262 

covers, when plate steel 7 5 

in a dished head 49 198 

frame, riveting of 65 260 

frame, proportions of 66 261 

gaskets, bearing surface of 67 263 

in any fire tube boiler, over 40 in. diameter 67 264 

Manufacture (See specifications) 

Manufacturer's stamp 79 332 

Manufacturer's stamp, not to be covered 80 334 

Materials, selection of 7 1-13 

Maximum allowable working pressure 

braced and stayed surfaces 49 199 

shells of power boilers 43 179-180 

Methods of support : 78 323-325 

Morison furnaces 63 243-244 

Mud drums, material of 8 10 

Muffler on safety valves • 73 279 

N 

Non-return stop valves, automatic . 76 303 

Nozzles, material of , 8 12 

Nozzles and fittings 76 299 

Number of gage cocks 75 294 

Numbers, serial 79 332 

O 

OG flanged construction 8 13 

Openings, threaded to be reinforced 68 268 

Outside screw and yoke valves, on steam pipe 76 301 

Outside screw and yoke valves, on water column. 75 293 

P 

Pins in braces, diameter of 55 223 

Pipes, bottom blow-off and fittings, power boilers 77 308 

feed and fittings , 77 314-317 

in steam space 75 290 

main steam, valves on 76 301 

or nipple, number of threads into fitting 76 300 

or nipple, number of threads into fitting, table 68 268 

surface blow-off and fittings 76 307 

threads, minimum number of 68 268 

water column, and fittings 78 320 

Piping, feed 77 314-318 

Pitch of rivets 44 182 

of rivets 95 410 

stay-bolts 50 199 

stay-bolts, table 51 203 

stay tubes 59 233 



INDEX, NEW INSTALLATIONS OF POWER BOILERS 



137 



PAGE 

Planing edges of plates 65 

Plate, steel, specifications for 11 

Plates, thickness, in shell or dome after flanging 9 

minimum thickness of in a boiler 9 

minimum thickness of stayed fiat surface 49 

Plugs, fusible 113 

Pressure, allowed on shell or drum, formula for, power boilers 43 

maximum allowable working, on flat surfaces, power boilers 49 

maximum allowable working, on shells, power boilers 43 

parts over 2 in., material of 8 

parts of superheaters, material of 8 

Pump, to supply feed water 78 

Purves furnaces 63 

R 

Reinforced threaded openings in shell, heads or drums 68 

Reservoirs, on steam mains 76 

Rings, waterleg and door frame, material of 8 

Rivet holes, finish and removal of burrs 65 

iron, specifications for 31 

steel, specifications for 15 

Riveted joints (See joints) 

Riveting 65 

Rivets 

allowable shearing strength of 8 

in braces, area of 55 

in shear on lugs or brackets 79 

in shear on manhole frames 65 

length of and heads for 65 

machine driven 65 

material of 8 

to completely fill rivet holes 7~. 65 

Rolling, ends of shell plates 45 

S 

Safety, factor of, for power boilers 43 

Safety valve 

blow-down adjustment 74 

capacity, method of checking 107 

connections, power boilers 73-74 

construction 74 

discharge capacity, power boilers 68 

discharge capacity, table of 70-72 

escape pipe for 73 

formula for 107 

method of computing and checking 107 

muffler on 73 

power boilers 68 

required on boiler 68 

seats of 69 

setting of . 68 

size limits, power boilers 69 

stamping of 69 

superheater 74 

test of 73 

Saw-tooth type of butt and double strap joint 103 

Screwed stays, supporting of 54 

Seamless tubes, specifications for 40 

Seats of safety valves 69 

Sections of cast iron, to be tested 87 



PAR. 
257 

23- 39 

18 

17- 20 
199 

428-430 
180 
199 

179-180 
9 

11 
318 
243 



268 
305 

13 
253-254 
121-138 

40- 62 

253-256 

16 
223 
325 
260 
255 
256 



255 
191 



180 

281 

422-427 

276-278 

280 

289-290 

282-287 

270-274 

278 

421 

421-427 

279 

269-290 

269 

272 

271-281 

272 

273 

288-289 

275 

417 

219 

164-178 

272 

372 



138 INDEX, NEW INSTALLATIONS OF POWER BOILERS 

PAGE PAE. 

Segment, area to be stayed 53 214-217 

of head, to be stayed 53 213 

method of determining net areas, water tube boilers 53 215 

Segments, table of 106 420 

Selection of materials 7 1-13 

Serial number 79 332 

Setting of safety valves 68 271 

Settings, power boilers . . . . 78 323-328 

Setting of wet bottom power boilers 79 326 

Shearing strength of rivets ... 8 16 

Shell or drum, longitudinal joints of 45 187-190 

Shell or drum, to determine allowable pressure on, new boilers 43 180 

Shell plate, thickness of 9 17- 20 

Shut-off valves on water column pipes . 75 293 

Sizes of flanged fittings, tables 110-111 

Sling stays 60 235-236 

Specifications for gray iron castings 26 95-110 

lap welded and seamless boiler tubes. . 40 164-178 

malleable castings 29 111-120 

plate steel 11 23- 39 

refined wrought iron bars 37 151-153 

rivet iron 31 121-138 

rivet steel 15 40- 62 

stay bolt iron 34 139-150 

stay bolt steel 19 63 

steel bars 19 64-76 

steel castings 22 77-94 

Stamping boilers A.S.M.E. std 79 332 

Stamps, A.S.M.E. std., location of 80 333 

Stamps, not to be covered by insulation 80 334 

Stamps, to be visible on shell plates, furnace sheets and head:; 79 331 

Stay bolted surface, to compute allowable pressure on 49 199 

Stay bolts 

adjacent to edges of stay-bolted surface 51 205 

adjacent to furnace door or other opening 52 206 

adjacent to furnace joint, v.t. boiler 60 238 

diameter of, how measured 52 208 

ends of 50 200-202 

211 

holes for 52 210 

iron, specifications for 34 139-150 

material of 7 7 

maximum allowable stress on • 54 220 

pitch of 49 199-204 

steel, specifications for . 19 63 

tables of allowable load on 104 418-419 

Stayed and braced surfaces 49 199-233 

Stayed flat surface 49 199 

Staying heads 55 222 

heads h.r.t. boiler 36 in. or less diameter 56 225-229 

dished heads 49 196 

furnaces 52 212 

segments of heads 53 213 

segments of he?ds with manhole opening 54 218 

Stay-rods, ends riveted over, to be supported 54 219 

Stay-tubes 58 232-233 

Stays, crown bars and girders 58 230 

cross sectional area in calculating 52 209 

diagonal and gusset, stresses in 54 221-222 

224 

maximum allowable stress 54 220 

s'ing 60 235-236 



INDEX, NEW INSTALLATIONS OF POWER BOILERS 139 

PAGE PAE. 

Stays, tables of allowable load on 1C4 418-419 

screwed, supporting of 54 219 

upset for threading 52 211 

and stay-bolts, allowable stress on 54 220 

and stay-bolts, table of allowable stress on 104 418-419 

Steam gr.ge and connections, power boilers 75 296-298 

mains 76 305 

mains, reservoirs on 76 305 

outlets 76 301 

Steel bars, for boiler parts 7 6 

castings, specifications for 22 77- 94 

crushing strength of plate 8 15 

for rivets, specifications for 15 40— 62 

for stay-bolts, specifications for 19 63 

plates exposed to fire 7 2 

plates when firebox quality not specified 7 3 

plates, shearing strength of 8 16 

stays and stay-bolts 49 199-212 

wrought or cast, for boiler and superheater parts 8 11 

plate, crushing strength of 8 15 

plate, specifications for 11 23— 39 

plate, tensile strength of 8 14 

Stop valves (See valves) \ 

Straps, butt, of equal width 103 417 

Straps, butt, saw-tooth 103 417 

Superheater drains 76 306 

safety valve on 74 288-289 

tubes and nipples 64 251-252 

Superheaters and mountings, material for 3 11- 12 

Support, methods of, for boilers 78 323-326 

Support, of stays, ends riveted over 54 219 

Surface blow-off 76 307 

Suspended type of setting h.r.t. boilers 78 324 

T 

Table of angles for staying heads 56 225 

constants for pitch of stay tubes 59 233 

discharge capacities of spring-loaded safety valves 69-72 

flange fittings, standard 110 

flange fittings, extra heavy Ill 

maximum allowable pitch of stay-bolts, ends riveted 51 204 

maximum allowable stresses for stays and stay-bolts 54 220 

minimum pipe threads for boiler connections 68 268 

net areas of segments 106 420 

round braces or stay rods, allowable loads 105 419 

stay-bolts, allowable loads, 12 threads per inch . 104 418 

stay-bolts, allowable loads, 10 threads per inch 105 418 

thickness of butt straps 9 19 

Tensile strength of steel plate 8 14 

Test, hydrostatic, of power boilers 79 329-330 

of safety valve, power boilers 73 275 

of steam gage 75 298 

gage, connection for 75 298 

Thickness of corrugated or ribbed furnace 64 244 

required for boiler plates 9 17 

required for butt straps 9 19 

required for dome plates after flanging 9 18 

required for shell plates 9 18 

required for tube sheets 9 20 

required for tubes 10 2 1~ 22 

Threaded openings 68 268 



140 



INDEX, NEW INSTALLATIONS OF POWER BOILERS 



PAGB 

Threads, pipe or nipple into fitting 76 

Threads, table '. 68 

Tin, for fusible plugs , . . . 113 

Truncated cones, maximum allowable working pressure on 58 

Tube ends, fire tube boiler • 64 

ends, water tube boilers and superheaters 64 

for fusible plug ' 113 

heads, staying upper segments of, by steel angles 50 

heads, of water tube boilers 53 

holes and ends 64 

holes, diagonal, in shell or drum 47 

holes in shell or drum * 46 

holes, sharp edges to be removed 64 

sheets of combustion chambers 59 

sheets, minimum thickness of 9 

sheets, space allowed unstayed between tubes and between tubes and shell 53 

Tubes for fire-tube boilers, thicknesses of 10 

for water tube boilers, thicknesses of 10 

lapwelded and seamless, specifications for 40 

required thickness 10 

stay 58 

Y 

'Valves, automatic, on water glass . . . 75 

automatic non-return stop 76 

extra heavy, on bottom blow-off 77 

extra heavy, on main steam pipe 76 

globe, not to be used on blow-off 77 

globe, on feed pipe 77 

on bottom blow-off 77 

on every steam outlat 76 

on feed pipe 77 

on Lamphrey fronts 78 

outside screw and yoke type, on steam pipes 76 

outside screw and yoke type, on water column 75 

safety (See safety valves) 

stop 76 

stop, drains for .-. 76 

Vertical boilers, furnaces of 60 

fire-tube boiler, manhole in 67 

fire-tube boiler, waterleg and door frame ring 8 

W 

Washout holes, power boilers 67 

Water column and connections, power boilers 78 

column and connections, power boilers 75 

glass and gage cocks, location of, power boilers . 75 

glass, automatic valves not allowed 75 

tube boilers, cast iron for headers of 64 

tube boilers, flaring of tube ends 64 

tube boilers, thicknesses of tubes of . . 10 

tube boilers, wrought or cast steel, parts of 8 

Waterleg rings, material of 8 

Welded joints 45 

Welded stays 52 

Wet bottom boilers, height from floor line 79 

Working pressure, maximum allowable, power boilers 43 

Wrought iron (See iron) 
Wrought steel <See steel) 



PAR. 

300 

268 

428 

231 

250 

252 

429 

225-229 

215 

248-252 

193 

192 

249 

234 

20 
216 

22 

21 
164-178 

21- 22 
232-233 



292 

303 

311 

302 

308 

314 

308-311 

301 

317 

319 

301 

293 

301-304 
303-304 
237-238 
264 
13 



265-267 

320-322 

295 

291-292 

292 

246 

251 

21 
9 

13 
186 
209 
326 
179-180 



INDEX TO RULES FOR NEW INSTALLA- 
TIONS OF HEATING BOILERS 



A PAGE PAB. 

Access and firing doors, heating boilers 86 370 

Allowable working pressure, heating boilers 81 338-340 

Allowable working pressure, existing installations, steam heating boilers.. 90 383 

Altitude gages . , 85 362 

Area, grate surface, table to determine size of safety valves 84 356 

B 

Blow-off cock, heating boilers 86 364 

Blow-off piping, heating boilers 86 364 

Boiler wet bottom, distance from floor line, heating boiler 86 369 

Butt and double-strap joint 

double riveted 97 41? 

triple riveted 98 414 

quadruple riveted 99 415 

quintuple riveted 101 416 


Cast iron boiler 

hydrostatic pressure test of 87 372 

maximum pressure allowed on 87 374 

section to be tested 87 372 

Connections, flanged 82 346 

Crushing strength applied to joints 95 410 

D 

Damper regulator, connected to steam space. . . '. 86 365 

Diameter of fusible metal in fusible plug 113 429 

Door, access and firing, minimum size of, heating boilers 86 370 

Down-draft boilers, safety valves for 85 359 



Efficiency of riveted joints, to calculate 95-103 410-417 

Escape pipe, from safety valve, heating boilers 83 355 

Existing installations, steam heating boilers 90 383 

Extra thick tube, for fusible plug. 113 429 

Factors of safety for steel heating boilers 81 340 

Fittings and appliances, heating boilers 86 364-368 

Flange fittings, tables of sizes of 110-115 

Flange steel, for heating boilers 81 337 

Flanged connections, heating boilers 82 346 

Fusible plugs 113 428-430 

Fusible plugs, location of 113 430 

141 



142 INDEX, NEW INSTALLATIONS OF HEATING BOILERS 



PAGE PAR. 

Gage, altitude .' 85 362 

cocks, heating boilers 86 367 

steam and connections, heating boilers 85 361 

water glass, heating boilers 86 366 

Gas fired boilers, safety valves for 85 360 

Grate surface, table of, for safety valves 84 358 

II 

Heating boilers 81 335-377 

Heating boilers, to which the rules of power boilers shall apply 81 335 

Holes for wash-out, heating boilers 82 345 

Hot water boilers 81 335-377 

Hydrostatic pressure test 

heating boilers 87 372-374 

on sections of cast iron boiler 87 372 

I 

Inspection at shop, heating boilers 87 375 

J 

Joints, butt and double strap, double riveted, example of 97 413 

butt and double strap, triple riveted, example of 98 414 

butt and double strap, quadruple riveted, example of . 99 415 

butt and double strap, quintuple riveted, example of 1C1 410 

efficiency of detailed methods of calculation 95 410 

heating boilers 82 341-344 

i lap, double riveted, longitudinal or circumferential, example of 96 412 

lap riveted, allowed on shell or drum not over 36 in. diameter 45 188 

lap single riveted, longitudinal or circumferential, example of 96 411 

longitudinal lap joints on heating boilers 82 341 

longitudinal of h.r.t. boiler to be above the fire line, heating boilers. . 80 371 

longitudinal, maximum length of, heating boilers 82 342 

protection of 82 344 

. L 
Lap joints 

length of, heating boilers 82 342 

longitudinal or circumferential, single riveted 96 411 

longitudinal or circumferential, double riveted 96 412 

longitudinal hot water boilers 82 343 

longitudinal, steam heating boilers 82 341 

Location of fusible plugs 113 430 

Longitudinal joints, steam heating boilers 82 341 

Longitudinal joints, hot water boilers 82 343 

Longitudinal joints of h.r.t. boilers to be above the fire line 86 371 

Low pressure steam boiler 81 335-377 

M 

Manufacturer's name, heating boilers 87 377 

Materials, selection of, for heating boilers 81 335-337 

Maximum allowable working pressure, heating boilers 81 338-340 

N 

Name, manufacturer's, on heating boilers 87 377 



INDEX, NEW INSTALLATIONS OF HEATING BOILERS 143 
O 

PAGH PAR. 

Oil-fired boilers, safety valves for 85 360 

Openings, flanged connections, heating boilers 82 346 

P 

Pipes, bottom blow-off and fittings, heating boilers 86 364 

Pitch of rivets 95 410 

Plugs, fusible 113 428-430 

Power boiler requirements for certain heating boilers 81 335 

Pressure, allowed on cast iron boilers ' 81 338 

maximum allowable working, old boilers, steam heating 90 38y 

maximum allowable working, heating boilers 81 338-340 

Protection, of joints 7 82 344 

R 

Regulators, damper 86 365 

Relief valves for hot water boilers 83 349-350 

Riveted joints (See joints) 

S 

Safety, factor of, for steel plate heating boilers. . . 81 340 

Safety valve connections, heating boilers 83 347 

Safety valve 

construction, heating boilers 84 356-358 

escape pipe for heating boilers 83 355 

for down draft boilers 85 359 

for heating boilers 83 347-360 

for oil and gas fired boilers 85 360 

for formula for heating boilers 83-84 351-358 

required on heating boilers 83 348 

seats of, heating boilers 84 357 

setting of, existing installations, heating boilers 83 348 

size limits, heating boilers 83 351 

stamping of heating boilers 84 357 

table of, for heating boilers 84 356 

Saw-tooth type of butt and double strap joint 103 417 

Setting of safety valves, existing installations, heating boilers 83 348 

Settings, heating boilers 86 369-371 

Setting of wet bottom heating boilers 86 369 

Shop inspection of heating boilers 87 375 

Sizes of flanged fittings, tables 110-111 

Specifications for material, heating boilers 81 336 

Steam gage and connections, heating boilers 85 361 

Steam heating boilers, existing installations 90 383-384 

Steel plate heating boilers 81 335-340 

Straps, butt, of equal width 103 417 

Straps, butt, saw-tooth 103 417 

T 

Table of flange fittings, standard 110 

of flange fittings, extra heavy Ill 

of sizes of safety valves, heating boilers 84 358 

of stay-bolts, allowable loads, 12 threads per inch 104 418 

of stay-bolts, allowable loads, 10 threads per inch 105 418 

Test, hydrostatic, of heating boilers 87 372-375 

Thermometers on hot water boilers 86 363 

Threads, table 68 268 



144 INDEX, NEW INSTALLATIONS OF HEATING BOILERS 

PAGB PAK. 

Tin, for fusible plugs 113 428 

Tube for fusible plug 113 429 



Valves, safety (See safety valves) 

W 

Washout holes, hot water boilers 82 345 

Water column and connections, heating boilers 86 368 

glasses, heating boilers. . . .' 86 366 

relief valves for hot water boilers 83 349-350 

Wet bottom boilers, height from floor line, heating boilers 86 369 

Working pressure, maximum allowable, steam and hot water boilers 81 338-340 



INDEX TO RULES FOR EXISTING INSTALLATIONS. 



A. PAGE PAR. 

Additional safety valves, existing installations 92 393 

Age limit for lap seam boilers. 89 380 

Allowable working pressure, existing installations 89 378-384 

B 

Blow-off cock, existing installations. 9S 401-403 

Blow-off piping, existing installations 93-94 401-105 

B.t.u. of various fuels 109 427 

Butt and double-strap joint 

double riveted 9 7 413 

triple riveted , 9 8 414 

quadruple riveted -— " 415 

quintuple riveted 101 416 

C 

Capacity of safety valves, examples of checking 108 423-426 

Capacity of safety valves, method of checking, existing installations 91-92 391-392 

Cast iron headers, maximum pressure allowed on, existing installations 90 382 

Check valve on feed-pipe, existing installations 94 406 

Checking safety valve capacity, method of, existing installations 91-92 391-392 

Cock (See valves, gage cocks, blow-off cocks) 

Crushing strength of steel plate, existing installations 90 387 

Crushing strength, applied to joints _ 95 410 

D 

Damper regulator connected to water column, existing installations 93 397 

Diameter of fusible metal in fusible plug 113 429 

Diameter of rivet holes, old boilers 91 388 

Drains from stop valves, existing installations 93 400 

E 

Efficiency of riveted joints, to calculate^ _ 95-103 410-117 

Escape pipe, from safety valve, existing installations 92 394 

Extra thick tube, for fusible plug _ * 113 429 

F 

Eactors of safety for existing boilers 89 379 

Factors of safety for second-hand boilers 90 381 

Eeed piping, existing installations 94 406-406b 

Fittings and appliances, existing installations 92-93 395-407 

Fuels, heats of combustion of 109 427 

Fusible plugs _ 113 428-430 

Fusible plugs, location of 113 430 

G 

Gage cocks, existing installations , 92 390-396a 

Gage, steam and connections, existing installations -__ _ 93 398-398a 

Gage, water glass, existing installations ... 92 395-396 



145 



146 



INDEX TO RULES FOR EXISTING INSTALLATIONS. 



H PAGE PAR. 

Headers, cast iron, existing installations 90 382 

Heating boilers, existing installations 90 383-384 

Heat of combustion of various fuels 109 427 

Hydrostatic pressure test, old boilers 94 408-409 

I 

Iron wrought, tensile strength, existing installations.— __. 90 385 

J 

Joint, butt and double strap, double riveted, example of 97 413 

butt and double strap, triple riveted, example of 98 414 

butt and double strap, quadruple riveted, example of 99 415 

butt and double strap, quintuple riveted, example of '. 101 416 

efficiency of, detailed methods of calculation 95 410 

existing boilers _ 89 380 

lap, double riveted, longitudinal or circumferential, example of 96 412 

lap crack 90 384 

lap riveted, allowed on shell or drum not over 36 in. diameter ___ 45 188 

lap single riveted, longitudinal or circumferential, example of 96 411 

L 

Lamphrey fronts, valves on existing installations 94 407 

Lap joint crack 90 384 

joints, longitudinal or circumferential, single riveted 96 411 

joints, longitudinal or circumferential, double riveted 96 412 

joints, longitudinal lap crack 90 384 

Location of fusible plugs 113 430 

Longitudinal joints, lap crack .__ 90 384 

M 

Maximum allowable working pressure, existing boilers 89 378-384 

Mud drums, maximum allowable working pressure 90 382 

P 

Pipes, bottom blow-off and fittings, existing installations 93-91 401-405 

Pitch of rivets 95 410 

Plugs, fusible 113 428~<30 

Pressure, allowed on shell or drum, formula for existing installations 89 378 

Pressure, maximum allowable working, old boilers 89 378-384 

R 
Riveted joints (See joints) 

Rivets, allowable shearing strength of, existing installations 90 386 

Rivets, existing boilers, diameter of 91 388 

S 

Safety valve, test of existing installations 91-92 391 

Saw-tooth type of butt and double strap joint 103 417 

Second hand boilers 90 381 

Setting of safety valves, existing installations 91 390 

Shearing strength of rivets, existing installations 90 386 

Shell or drum, to determine allowable pressure on, existing boilers 89 378 

Steam gage and connections, existing installations 93 398 

Steam outlets, existing installations 93 399 

Steel, tensile strength of, existing installations &0 385 

Stop valves (See valves) 



INDEX TO RULES FOR EXISTING INSTALLATIONS. 



147 



T PAGE PAR. 

Table of sizes of rivets, existing boilers 91 388 

Tensile strength of steel or wrought iron, existing installations 90 385 

Test, hydrostatic, existing installations 94 408-409 

Test, of safety valve, existing installations 91-92 391 

Tin, for fusible plugs 113 428 

Tube for fusible plug 113 429 

V 

Valves, on bottom blow-off, existing installations 93 401-403 

on feed pipe, existing installations 94 406 

on Lamphrey fronts, existing installations 94 407 

safety (See safety valves) 

stop, existing installations 93 399 

stop, existing installations, drains 93 400 

W 

Water column and connections, existing installations 93 397 

Water glasses, existing installations 92 395 

Working pressure, maximum allowable, existing installations 89 378-384 



<*A 



£• 
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